I recently purchase a Thermaltake Duorb for my new 8800 GTS G92 card to replace the factory reference cooler. (The card is brand new and has not been in the machine yet. Previous card was a 7800 GTX)

After assembly and installation I fired up the PC. (Running MCE2005)
The PC started to boot as normal. It did the POST check and gave me the chance to hit DEL key to enter the BIOS. I hit it to enter the BIOS. Then my screen went blank and the actual monitor appeared to go into power save mode?!

I reset the PC as I couldn’t see anything so I was flying blind. This time I didn’t touch anything and allowed to it boot fully. Same thing occurred. I watched it do the POST check and directly after giving me the chance to hit DEL to enter the BIOS, the screen again went blank. I resisted the temptation to hit any key and let the machine go. The HDD activity light was busy flashing so I assumed something was going on, I just could not see what. Eventually my VFD on the case came on (in about the normal time it used too during the boot sequence), so I’m assuming all is well with the HDD as the boot appeared to work a-ok… problem is I can’t see anything on my screen and as it appears, directly after that point in the POST check, the monitor looses the signal as it goes into power save (i.e like no PC connected). I did this another 3 times (5 times in total) and in each instance the same thing occurred.
My rationale:
HDD ok as VFD came on therefore boot process occurred
VGA card is ok as I can see the Motherboard wallpaper at boot and the "Press DEL to enter setup" statement
Power supply 550w should be plenty for this card upgrade
I would have assummed that the boot would have been as normal and once in the Windows environment, it would have detected a new card requested drivers etc.. Obviously a wrong assumption...
Over to the clever people for suggestions/fixes.... please....