Received a PC that was effectively DOA. PC is a home build and has previously worked for 1 year. Case fans and heat sink fans would spin. Power to HD, Optical drives, and graphics card. Thought it was MB. Took HD out of PC1 and Installed on PC2. Booted right up. Took memory out of PC1 and installed working memory from PC2 into it. Powered up but ended with BSOD and auto reboot. Tried Memory from PC1 in PC2 and PC2 would not boot. Ah ha. Removed good memory from PC1 and tried reinstalling the bad memory 1 stick at a time. Did not boot to first stick. Booted to second stick but again ended with BSOD and auto reboot cycle. Again removed HD and installed it on PC2 and again it booted no problem.
Here's where I'm at now. I know I have 1 bad stick of RAM. I'm confused as to why the HD will not boot on PC1. Is it indicative of a possible bad MB. When I try to boot it gives me the "Windows was not shut down properly" message and the options of "Start Windows Normally, Start in Safe Mode, etc" but USB Keyboard does not work. It powers for a second and then freezes and does not respond to enter or any key strokes. After 30 seconds it attempts to start normally, then right before it finishes booting BSOD flashes and auto reboot cycle begins. I'm not sure how to proceed. Any help would be greatly appreciated.
Your post is not very useful to me without specs. Switching memory between PC's doesn't mean much unless we know for certain that the boards are both fully compatible with the RAM and the settings in BIOS are 100% proper.
Welcome, Newcomer. Aside from hardware failure, there could be a corruption in the OS (typically the boot sector) that is preventing a successful boot. First thing you should do is put the questionable HD in PC2 (assuming that there is no USB problem as experience with PC1) and power it up. Press the F8 key immediately and repeatedly after powering on PC2. You should be taken to an Advance Boot Options (or something like that). If you can, select the option to disable restart on boot failure. The computer will restart on its own and should "freeze" on the Stop Error screen, or commonly referred to as the Blue Screen Of Death (BSOD) .
This screen should give you some info as to what the failure is. Post back with the contents of the message.