I'm having troubles with my system and can't figure out the cause. After a several trials with this system I started up completely from scratch. I'm having an Asus Motherboard M2A VM HDMI, running well and installed the latest BIOS to be sure that this couldn't give me any troubles. 4 Gb CrossAir Mb. An AMD Quadcore 9550. A 1 TB Western Digital Sata HD and a Benq DVD R/W. The rest is Disabled or disconnected to be sure nothing will interfer. Even the Harddisk has been backuped, formatted, unpartitioned and completely wiped (took more than 10 hours) and formatted again. After installation of Win7, which took about 18 minutes, without connection to the internet to disable any auto-update (with autopdate the same thing happens), everything runs well with this version of Win7 (build 7600). Then running updates and installed Microsoft Security essentials and some standard software such as Adobe Reader and Adobe Flash Player my system suddenly hangs for more than 5 minutes. I can't startup anything. Even not giving an CRTL+ALT DELETE activation. The only thing hapenning is that the Hard Drive lights continous lighting up. That could mean Bad Sectors or something like that but I did a check with the original Western Digital Harddrive software to check the drive but no errors are found. Even not with the extended check with the software Western Digital dlgdiag.exe. Taking a look at Taskmanager nothing seems to be interfering. All uncommon applications are been shut down by me. All auto startup events are also been disabled besides Security essentials offcourse. All Latest update are installed. No other software running. Device Manager gives not warnings at all. Everything looks fine. But after startup and running IExplorrer for instance this system hangs again. Did a several Safe Mode Startups and that sort of thing without any result. Also repair from a Repair Disk (DVD). I can't figure it out. Running out of options I connected a 20 gb old IDE HD as test HD to this system after formatting the 1tb HD again and disabled it. Installed Win7 at this 20gb HD with Office 2007 and some other software and the strange thing is that it runs well on this small 20gb HD. Super fast system. WHY,WHY,WHY? I did everything was was possible but I can't install this Win7 on this 1TB HD. I'm busy with it for more than one week and can't figure it out. Why seems everything well and do I get this weird problem some minutes after startup. System Hangs continous, waiting for something and goes further when HD activity stops. Any clou?