Whenever I watch videos online (YouTube etc.) Vista crashes after 15 min. or more. My system in completely stable otherwise. Any suggestions would be welcome.

Vista & SP1
Intel C2D E4500
GA-P35-DS3L
4G-OCZ2P800R22GK PC6400
eVGA / Forsa GEFORCE 8500GT 256MB
Seagate 320GB 7200RPM
OCZ StealthXtreme 600w SLI
Coolermaster 690 Case
Download and install Speed Fan

Post what the temperature READINGS are.CPU is 34C IDLE and got up to 46C doing a benchmark.
Board temps are 34C.Hmmm.....TEMPERATURES look fine.

When did this problem start?

Also, what Internet Browser?The OP is getting suppressed Blue Screens of Death.

OP: please do this:

Start -> Control Panel -> System -> Advanced System Settings (upper left hand corner) -> under "Startup and Recovery," click the Settings button -> uncheck "Automatically Restart" -> Apply -> OK.

Try watching a VIDEO online again. This time, the machine won't reboot. You'll get the REAL Blue Screen of Death.

Write down EVERYTHING on the Blue Screen and post it here.not the same person but i have the same thing happening

BSoD says the following: (shortened)

Quote

APC_INDEX_MISMATCH
*** STOP 0X00000001 (0X9E444C41,0X00000000,0XFFFF0000)
*** WIN32K.SYS base at 9E444C410000 datestamp 49edb076