Hello everyone, I'm having some troubles with a PC and as the title of the thread says the PC doesn't load the Operating System neither the BIOS. One day I turned on the PC and when I logged in the computer crashed. PC specifications: ACER Aspire M5641 R01-B4 Board: ACER MCP73PV NVIDIA MCP73 Processor: E2200 2.20 gigahertz Intel Pentium Dual BIOS: American Megatrends Inc. R01-B4 09/11/2008 Chipset: NVIDIA GeForce 7100 / NVIDIA nForce 630i Hard Drive: WD 640GB RAM: 3GB: -2GB Acer DDR2-800 PC2-6400 non-ECC DIMM <-This memory card stopped working at the same time as this issue occurred -1GB Acer DDR2-800 PC2-6400 non-ECC DIMM OS: Windows 7 v6.1 RTM Built 7600 What I've tried: Repair and Reinstall OS: -I had access in safe mode only once, after that I couldn't login again. I extracted the logs from Event Viewer but I didn't find anything relevant or something related to the problem. -When I boot from the CD/DVD it loops loading the configuration files; I tried with WinXP and Ubuntu to see what happens but the same issue occurs it loops loading the files and never starts the wizard for the installation. Memtest86 -I tested the two memory cards in other computer and these were the results: >One of the mems passed successfully but the other one crashed and never ended the test. >So I'm using the memory that is working but that didn't solved the issue BIOS reset: -This didn't work. It seems that the Mobo tries to run the BIOS but for one or other reason crashes. BIOS upgrade: -I couldn't even run the utility to upgrade the BIOS, happens the same as when I try to get into the BIOS, the screen freezes and I can't do anything. Any ideas? Thx in advance.