My turn..Driver IRQL NOT LESS OR EQUAL - help please

After trying different things, I decided to post my minidump's here for you to look at..

I tried mem test = passed.

Now I really don't feel like reinstalling XP, but if I can locate the problem driver this would be better..

Specs:
AMD Athlon XP 3000+
Gigabyte GA-7N400 Revision 2.0
2 512Meg PC3200 Ram (400 Mhz)
Geforce 5600XT Ultra
SB Live 5.1

Hi,

Probably your problem is related to faulty ram or PSU.

Your debug report
Mini122405-01.dmp BugCheck 1000000A, {ffd7f980, 1e, 1, 804e3919}
Owning Process 85ebb8f0 Image: Sims2.exe
Probably caused by : portcls.sys ( portcls!CServiceGroup::RequestService+5d )

Mini122405-02.dmp BugCheck C2, {7, cd4, 10001, 85adc290}
Owning Process 863cb830 Image: System
Probably caused by : SiWinAcc.sys ( SiWinAcc+325 )

Mini122405-03.dmp BugCheck 1000000A, {4100, 2, 0, 805138e3}
Owning Process 853b83c8 Image: Sims2.exe
Probably caused by : hidusb.sys ( hidusb!HumReadReport+ed )

Mini122405-04.dmp BugCheck 1000000A, {fdd8c14, 2, 0, 804f10fa}
Mini122405-04.dmp DEFAULT_BUCKET_ID: COMMON_SYSTEM_FAULT
Owning Process 85285518 Image: Sims2.exe
Probably caused by : portcls.sys ( portcls!CPortPinWaveCyclic:eviceIoControl+1fc )

Mini122405-05.dmp BugCheck 100000D1, {85cc23d0, 2, 0, ef3c8008}
Mini122405-05.dmp DEFAULT_BUCKET_ID: COMMON_SYSTEM_FAULT
Owning Process 852eb638 Image: Sims2.exe
Probably caused by : HIDCLASS.SYS ( HIDCLASS!HidpInterruptReadComplete+13e )