Computer turns off without warning

[hidde]

Help...!

I have the following hardware:

650W power supply (spire 650w)
AMD Athlon-64 X2 5000 AM2 Box
4gb DDR2 PC6400 memory
WD SATA Raptor 74GB 10.000rpm
ATI Fire GL V7200 256 MB PCI3 Card (driver 6.14.10.6392)
Mobo ASUS M2N-SLI deluxe (we had MSI K9N platinum, we changed but it did not matter it seems)
19gb swap (d:\)

Software:

Windows XP Prof. 64bit UK
Solidworks 2007 sp2.2 32bit (we lost the 64bit dvd , but it should not be a problem according to the solidworks resellers)

Problem:

The computer shuts down without warning and is not restarting when solidworks is running idle or when i use it. Our electrical installation is ok. The processor is running idle. This happens a few times per day.

I really dont know whats wrong

pls help me.

 

[hidde]

Bad news, it worked till 1 hour ago. It turnud off 3 times in a row... I will check ground and powersupply.

It turnes off most of the time when i use solidworks, but the last time it turned off when it was processing my login.