Cant Boot Into Windows 7 With SLI Enabled

[skulkingghost]

OK heres the deal, I currently have a BFG GTX 260 (core 192) in my system. I wanted to beef up performance a bit so I picked up a second GTX 260 today at microcenter (A PNY XLR8 core 216.)

Everything I have read says they should work fine together for sli. However upon hooking up the card, and attaching the sli cable I can not get into windows, the closest I can get is the starting windows screen of windows 7.

IF I let it sit for an hour it will take me eventually to an all black screen where I can move the cursor around, but nothing more.

Things I have tried:
Reseating and swapping PCI-E positions.
Reformat (cant even reformat with both cards in the system, I am going to take one out and try now)
Removing Nvidia drivers with driver cleaner and reinstalling
Checked the rails to make sure they were providing clean power to the system and they worked (all are perfect)


Rig Name: Skulks i7-920
CPU: Quad Intel I7-920 2670MHz
Motherboard: Asus P6T
Memory: 12000 MB of Crucial PC1600 DDR3
Video Card: BFG GTX 260 Nvidia Geforce
Hard Drive: OCZ Velocity SSD 120.0 GB
Additional Hard Drives: 4x 1TB WD Green
1x 320gb Seagate Barracude
1x 500gb WD
Monitor: 28" Hannspree HF289H
Additional Monitors: 20" Asus 2203W
DVD R/W: LG 52x DVD+-R/W
Storage Interface: SATA
Sound Card: Auzentech X-FI Prelude
Powersupply: Thermaltake 750w
Speakers: Logitech Z-5500
Internet Connection: Verizon Fios Cable @ 25/12mbs
Operating System: Windows 7 64bit

 

[mpilchfamily]

It sounds like you have a power issue. Your PSU just isn't quite able to run the system. Its fine in the bios because the system is only using the low level 2D on the cards. But as windows loads the drivers for the cards load up and the higher functions try to turn on and the PSU just can't handle the extra load.

 

[skulkingghost]

I thought the same thing too at first, but I did a power supply estimator and it came through fine, and I plugged the card in to a second power supply and I am still having the issues