A guy I know got three (3) Gateway's E6300 (Pent. 4 @3.6, 2x512 DDR2@400, 80GB SATA) from surplus; and they were is remarkably good and clean condition (not a single spec of dust inside). I was asked to set-up one with Win7. Install went OK, I have put on chrome, office, AVG and called it a day. Before I left office I ran full AVG scan. Next day I came into office (no one touched the PC) and while the PC was fully on, there was no video signal and no power going to USB devices, but HDD and all the fans were spinning. So I restarted the PC and while it did power up, there was still no video signal and no power going to USB devices, but HDD and all the fans were spinning. No post codes or beeps. So, I set that PC on side and set up the second one the same way. Before I left office I ran full AVG scan. I took the PC home (the first one), tested the PSU and HDD, both OK. Now when I booted, unlike in office, I got three long beeps (memory fault), so I took out both sticks and re-seated them. The PC booted normally. I ran boot diagnostics from CD which tests everything from HDD, to video card and memory and it came all OK. Ran MemTest86 from few hours and it too came up OK. Now I am staring at PC screen and the PC is still functioning. I even ran AVG several times to see if that would crash it, but nothing. Here is the kicker. I just got a call from the guy, that the second computer I set-up is not working. Again it was sitting turned on over night and it "crashed" the same exact way as the first one. Now, I still did not make it over to the office to check that out, but I would bet it is the same issue. What are the odds that two identical computers would stop working over night for same reason? The fact that I cannot crash the first computer at my home has me a little confused. Any thoughts? Keep in mind that both computers were fully functional for almost 24hours before they crashed, and no one touched them after I left. Thoughts?