After a pet-related mishap caused my son's computer to shut down I decided to contact Sam & Marcus with Expert Reaction based on them being local, and very highly rated here on Yelp. While they do "house-calls" this issue was a bit more serious, and so I coordinated with Marcus to drop off the computer so he could trouble-shoot the problem. (Note: their current location IS inside the yard for the auto body workshop.) I also left them with the brand new PSU I'd bought from Newegg, thinking it may have been the problem, but wisely deciding to use their services rather than have a go at it on my own. Because as it turned out it was NOT the PSU, but the motherboard and RAM, and after replacing those components Sam and Marcus were able to get the PC up & running. They also very considerately did not even open the PSU box, even leaving its shrinkwrap intact, making it an easy RMA for me. The lads stayed in contact with me during the entire process, which took a little over a week, from the initial diagnosis, to sourcing the new components, the installation, and then 'burn-in' to make sure there were no other issues. At the end of the day they get a well deserved, well-earned 5-star review. "Pet-mishap", remember? Let's say it was of "the worst kind" and leave it at that. Thanks Sam and Marcus! Your services are very much appreciated! read more

I just had the BEST experience with Sam: I couldn't connect to the internet from my home computer and called Expert Reaction because they make house calls. He arrived on time, isolated the problem as a bad cable INSTANTLY and repaired it in minutes. He also offered to swap out all my cables for new shorter cables which we did! He was soooooo knowledgeable and polite and comfortable to talk to. I am just thrilled with his service, dependability and professional, yet kind, demeanor!! I would recommend them to anyone, small job or huge job because I believe he and his partner would find your solutions!!!!! read more

This company deserves 5 stars, Sam is a knowledgeable, helpful and really a nice guy. Came to my location, scoped out the problem and gave me a great solution. Very reasonable and he works with you. I recommend him highly. Bill read more

Marcus helped me out and got my iMac running like a champ. Marcus was honest , always available to chat and answered all of my questions. He also fixed my iMac in one afternoon. Prices are fair and his work is great. Can't ask for anything more. Thank you Expert Reaction read more

We had an Asus desktop tower that was stuck in a bios loop after a power outage. Called the guys at Expert Reaction and Sam was able to come out to our house the very next day. He trouble shot the machine, determined the likely cause of the problem was the motherboard, got our basic functionality restored, and helped us decide to upgrade to a newer system for the long run peace of mind rather than just find a 2nd hand replacement of the current MB for the same price. For over three hours of work, it was a very reasonable flat fee. Sam was very knowledgeable and friendly and didn't give up when the problem proved trickier than expected. I can't say enough nice things about this experience. read more

The memory on my new Lenovo desktop was consistently at 98% usage. I'm running Windows 10. So it's not an unusual problem with this OS. I deleted some bloatware and tried about eight fixes from the web with no results. I found Expert Reactions on yelp, called them, and set up an appointment. I was happily surprised that someone could come out the next day, and he did. Sam checked out the problem, running some checks and trying some fixes. It didn't take long for him to find a memory leak, which he obliterated completely. Memory usage dropped to around 35% and the system runs smooth, clean, and fast. Sam is a totally righteous dude, polite, knowledgeable, punctual, communicative, and easy to talk to. In the event of future problems, I plan on calling ER and asking for Sam. The help he provided was worth every penny, and the cost didn't break the bank. Moreover, I plan on taking the tower in to get some more RAM installed. They do that on site. Highly recommended. You will not be disappointed that you called them. Ask for Sam. read more

Expert Reaction Computer Services - I'm happy with Expert Reactions' expert service. Call them. - IT Services & Computer Repair Near Me - Covina, California

Sam came to fix my parents' frozen, old computer. Mom uses it to watch YouTube so you know it was important. Expert Reaction answers their phones right away. Sam came the next day and thawed the computer. Macafee apparently was keeping it in the North Pole. Just glad they made house calls. read more

These guys are honest, knowledgeable, and fair priced, but best of all There when you need them. Maintaining Computer network systems Are like learning a new language. Three year old can do it But it takes years and most business owners don't have the time to spare Very very happy I found them read more

I came to find Expert Reaction through a referral from a friend. I've been using these guys for over 10 years, and it's worth every penny. The quality of service, and the builds they do are top notch. They're fairly priced, knowledgeable, and most importantly, honest and about the products they service and build. If they don't know the answer, they will tell you they don't know, but will do the research to find out. As a small business owner, these are traits of a great company. They've earned and deserve my business. read more

I had amazing service from this company and especially amazing service from Sam! Sam is extremely knowledgeable, patient and passionate about his work! He has provided service to our company when emergencies have occurred and always works in the best interest of the customer! I highly recommend this company for any of your needs! read more

Sam was professional, knowledgeable, and honest. This company deserves to have a line out the door. I highly recommend them for any computer needs. read more

Fantastic experience that began with my search here on Yelp. I was seeking a well trained and experienced professional to install a computer network for our growing business. After getting the run around from another local computer service, I called Expert Reaction. I had the pleasure of speaking with Sam, the co-owner. Sam scheduled an on-site meeting and arrived on time. Sam is very personable and was attentive in understanding our business needs. He thoroughly examined our existing system and made recommendations for hardware and software improvements. Sam offered several options based on our budget. We ultimately ended up with a new rack mounted computer server, gateway, and several workstations. He installed new network exchange software, and a real-time data backup system. To accommodate our remote employees, he configured their laptop computers and installed a VPN for secure communication. Everything is running smoothly now, and thanks to our new Teams application, employee communication and collaboration has improved significantly. Our business is now operating with improved efficiency. We are very thankful for Sam and Expert Reaction. This company truly lives up to its name. Please don't hesitate to call Expert Reaction Computer Services for help with your next project! read more

Marcus did a great job installing our network, data migration and setting up our server for our dental practice. We are very happy with his services and look forward to work with him in the near future. Marcus explained everything in a very easy way to understand. He also give us very useful recommendations. Highly recommended!! read more

Our business was dead in the water with our server in RAID failure Worse than that it is actually sinking with questionable back ups Sam was on it 2 minutes early and up and running in 60 minutes all data accessible and a new server on tap......very solid service read more

Years ago I had a very positive experience with Marcus of Expert Reaction. Recently I had an issue with another computer. I attempted to fix the issue myself. I wasted lots of time googling how to and even bought "fix it" software that did not help. I called on Expert Reaction again. This time around I had the pleasure of working with Sam. We made an appointment but I requested that if they could "squeeze me in" sooner, please do. They tried but, I was unavailable at the time that time. Sam took us in right on time. He was friendly, knowledgeable, and most certainly an expert. He fixed my computer issue and made a few tweaks to it that will make my life easier. The fee for the repair was more than reasonable. I couldn't be happier. read more

Amazing Service! They gave me the best deal possible and were realistic with me! They were also very patient and sincere in their words. They do not try to sell their business but focus on really helping the client in what they need! 100% recommend this repair shop! read more

Marcus was outstanding to work with. He assessed the issue, ran to get equipment, tested it to determine an issue, tried another way , no success and offered yet another solution. He has one satisfied customer. Took back the product that did not work and spent 2 hours getting to the root of our pc/ connectivity issues. read more

I forgot to make this review 1 year ago when I sought their help. I damaged my computer from a fall from yanking my power cord. The laptop wouldn't close correctly, so I looked up parts to replace the hinges. Just before purchasing, I sought advice from Expert Reaction, and their review said the computer chassis was slightly bent from the impact and that was what affected the computer. Then they said that quick review of my computer was on them. I'm so thankful for their kindness, that they saved me money with their assessment, and waived their assessment fee. I know that if I have any computer issues, I'll be turning to them! read more

Clumsy me, somehow managed to break the screen on my Samsung laptop :( I shopped around for a new laptop, and realized that wasn't an option.. Figured Best Buy could fix the screen, but for the quoted price, I might as well buy a new laptop.. Finally came across this Gem on yelp- glad I did. They quoted me a MUCH lower and reasonable price than Best Buy, took my laptop in on Monday and it was ready for pick up on Friday. Laptop works great, screen looks new (well it is new ha). The guys are definitely friendly, honest, and worked magic on my laptop-Highly recommend this place! read more

Took in my older PC and was able to sell it for a profit due to it being fixed. Bought a new high end pc and they were able to build it at a reasonable price. Will go back to them in a heart beat. read more

I was having issues with my laptop, the keyboard & mouse pad specifically. I spoke to Marcus and told him what was going on and asked for a pricing on what it would cost to fix it. I dropped off my laptop to him and he was able to get it fixed and back to me in a couple of days! The communication and customer service was great and I am so thankful to have my laptop back so quickly! read more

Needed my internal hard drive backed up, and they did it with no fuss or muss. Just called, made a same-day appointment, and got it back the next day. Their quote was pretty competitive as well. A++ will do business with again! read more

Expert Reaction lives up to its name, the reviews already speak to this. Sam and his partner drive right over to you and fix your IT problems lickety-split! No job is too small, I'm a one-woman office and they made me a priority. Will recommend these guys to all my friends. Great service + great attitude = grateful customer! read more

Great resource for computer repair. Professional, quick and easy access. They ran a diagnosis on my desktop and I was pleasantly surprised at how quickly they were able to do it. Marcus and Sam are very professional and are experts and very trustworthy. I will not hesitate to bring in any of my computers here for repair because i know it will be in good hands. Please do not ask the geek squad for your computer repair needs, Expert Reaction Computer Services is the place you want to go for your computer repair needs. read more

Expert Reaction is seriously awesome. Whenever I have computer problems of any sort, I call them and somebody is on their way in no time! I use their services extensively for my office because it's important that we don't get delayed during our busy work day. They even set up our computer networks, office software and all sorts of jazzy stuff that would probably take me days to figure out. read more

I'm a college student, finals are next week, and my Fing hard drive crashed. GeekSquad, the only other computer place around that's open on Sundays, was going to charge me at least $350 and it was going to take TWO TO THREE WEEKS (!!!!!!!) to fix! Ridiculous. Expert Reaction was booked for the day but they moved some things around to fit me in. I ended up paying under $250 and that's with data recovery. I'll be back. read more

I brought my son's laptop here for repair. The staff was professional, courteous, and the work was done promptly. It was also very easy to arrange an appointment. read more

Took my computer in and found out the hard drive had crashed. Everything went well. They recovered my files and the turn around to get my computer back was fast read more

I found these guys through yelp and brought in my computer due to the screen being broken. The assistance I received was top notch, Sam even tried to find a cheaper alternative rather than just ordering the more expensive part. He always returned my phone calls in a timely manner and answered all my questions. The service was also fast once the part came in. Overall, awesome computer repair place, good prices, and the guys here are very knowledgeable. read more

My family opened our business about a year ago and we needed a lot of work done to set up a network and all our computers. Sam did a great job with all that. There might be places that charge less, but one of the most important things we've learned is that you really do get what you pay for. If you want quality work and reliable service, Sam is your guy. read more

My MacBook Pro is 8-1/2 years old. A few years ago the battery died, but I just kept it plugged in all the time and it still worked. Last year the track pad warped, but I just used an external mouse and it still worked. The past week or so, I started to have problems with the mouse not working, and this morning it died completely. I thought my laptop had finally and totally crashed. That is, until I called Marcus at Expert Reaction! He had me bring in my laptop within the hour and he knew immediately what the problem was. The battery was old and old batteries have a tendency to bulge and warp the track pad. He had the right battery in stock and before the day was out had fixed my laptop. It works like new again...and the price for the battery and labor was more than reasonable. I couldn't be more pleased with the outstanding service I received. Thank you, Marcus, for turning what I thought would be a disaster into an easy fix! read more

I was having a problem with the charger on my laptop. I thought it was the connector on the charger and bought a new one. Turns out it was the jack in the laptop. After checking Yelp! I decided to call Expert Reaction. I made an appointment to drop off my computer. Easy to find location on Grand with lots of parking. Marcus was friendly and took a look at the problem and verified that it was the power jack, The next afternoon he called and said it was ready. When I picked it up the bill was exactly what he said it would be. When I got home I couldn't log on. My password didn't work. I called him and asked if he did anything and he hadn't. I brought it back in and he started looking at it and ran some diagnostics. He said it might take a couple of hours. I left and about an hour later he called and said it was ready. This was now after six at night. When I got there he powered it up to show me it was working. I asked how much I owed him for fixing it and he said nothing. I was willing to pay him but he refused. Great customer service. Quick and friendly. I highly recommend them. read more

Our company has been working with Expert Reaction for the passed year and we are extremely pleased with their services. The techs at Expert Reaction are very experienced and knowledgeable about what they are doing. There have been numerous times when our office has experienced unexpected technical problems and the staff members at Expert Reaction have been extremely reachable and always try their best to accommodate us. Sam goes above and beyond to provide excellent customer satisfaction and we are very happy to be working with someone we can trust and count on. I would highly recommended Expert Reaction to anyone. Thanks Sam! read more

I've worked with Sam and Marcus for years. They've helped me with viruses, hardware malfunctions, Internet issues, and printer setup for Macs...which is the most difficult thing next to building the pyramids. I admit, I've called them after hours before and someone still answered. I was just expecting to leave a message but I ended up talking to Sam for 15 minutes while he walked me through my wifi setup. read more

Awesome place highly recommend!!! they have the best service!!! had laptop running slow, having alot of problems not opening files gave it to them had it back with in the next day. I would recommend them to anyone!! they take your device but you would have to take it early in the morning but it's usually by appointment talk to marcus! read more

I am a small business owner of a cabinet shop and I have used them on several occasions, both in person at my office and over the phone with step by step help to resolve my issues. They were quick to respond and affordable, especially when you consider the time they saved me and we all know time is money!!! read more

I rarely give reviews but damn this place deserves it. I wanted to transfer all my hardware from one tower to a new tower and have all the cables to be nice and neat (cable management they call it). Well I went to geek squad first and they wanted $50 PER PART.. move the graphics card $50, move the ram $50.. etc... they were insane. Then I went to another cpu place in West Covina, they wanted $200. After that I called the place where I got my CPU (IBuypower in El Monte) and they wanted $250... FINALLY I called expert reaction $89!! and they were Extremely Helpful! I dropped both towers off.. they were done 4 hours later.. the inside of my CPU LOOKS BEAUTIFUL! and runs wonderful! Thank you again Sam! read more

I brought my computer in since it would not start. Marcus was great, started it up and had it fixed rather quickly. I was very impressed that all mr data were saved, and with the quality of the work. Highly recommend this place, which was half the price of Staples. read more

GREAT GUYS!!! Totally professional and you can get in contact with them all the time.

Professional and reasonable prices, no hidden fees or extra charges. I strongly recommend!