My issue is very strange. 2 days ago my laptop (Info: Compag Presario C551TU, Intel Celeron M 1.86GHz, 1GB RAM (DDR2-333), 80GB HDD Hitachi, Windows XP SP2--> an old laptop): - Worked well - Could be shutdowned, Hibernated and Started normally - I haven't installed any softwares from the beginning of this month - No Internet connection, no downloads ---> no viruses. However yesterday I started it up and just 1 second after the splash screen of MS Windows XP SP2, the laptop displayed a blue screen of death and restarted. It keeped displaying BSOD and restarting until I turned its power off. Today I use Hiren's Boot CD to test it. The results: - HDD: no bad sector. I can use MiniXP to access my HDD and copy important files to a USB flash drive. So I don't think the hard drive is damaged. - RAM: I use memtest86 and 100% passed, no error. I take the RAM piece out of the machine and clean it, too. - I use Norton Ghost to recover my C:\ drive but it doesn't work although I have used this ghost file many times to recover my computer damaged by viruses. I use MS Windows XP CD to do a fresh installation, but when I try to install, this error appears: Setup did not find any hard disk drives installed in your computer I've read some articles but I don't think they'll solve my problem because my laptop has the BSOD error by itself and I don't change any settings. The night before this problem I still could use it normally. I've never installed any other operating systems like Vista or 7. Could you please show me how to solve this strange problem?