Msi GTX260 T2D896-OC

Hi!
i have a HIPER psu type R II HPU-5B680 and i cant install my gtx 260 graphics card. I install it and then after i restart my pc, it freezes at loading screen after a while. Is my PSU compatible with the card?
I tried windows 7 and windows xp...

Here is what i have tried allready....
i had a 9600gt on windows 7. i unistalled the previeous drivers and i tried installing my gtx260 drivers. after reboot freezed.
i formated my pc and chenged back to windows xp. tried to install drivers, after reboot freezed.
at last i formated and installed windows 7. i haven't tried installing the card now, because i saw somewhere something about ambers issue from psu.
So my real question is if my psu is the problem. i know that it produces enough watts, but how about ambers?

(sorry for my english)

Start from the beginning:
Your power supply has plenty of Watts and amps, I ran a HD4870 from a weaker Hiper PSU without issues.

First, ignore the current card, get the 9600 working, so you can fully update Windows and DirectX.
With that done download Driver Sweeper and install it.
Redownload the Nvidia driver, you may have a corrupted download, it is rare but can happen.

SET A RESTORE POINT!

Power down and put the GTX260 back, making sure it is fully seated and locked into position. Connect BOTH 6 pin cables, making sure they are fully seated.
Now reboot and go into the BIOS and reset it to factory defaults, save and reboot.

If the lockup still happens:
Reboot into Safe Mode and uninstall any graphics drivers you find-ATI or Nvidia.
Run Driver Sweeper but remember: This type of software is not perfect and it can damage your system, so check everything and deselect any items that look wrong. This is why you set the Restore Point!
Reboot, you should boot normally this time because no drivers are installed but the graphics settings will be poor. Tell us if this fails.
If all is well, install the drivers you freshly downloaded and reboot.
Post back with the results, please.

you have four 12v rails with 18amps per rail. 680w total and peak at 890w. How old is your PSU? It could be damaged somehow but it does not lack power.

I have an Asus P5Q-VM motherboard and it has onboard vga adapter. Do i need to reinstall my old 9600gt? And my PSU is 3 months old. I know that it doesn't lack power, but i thought i coonect 2 6pin cables and that gives us 2x18A and that's not enough.

Ok... I was on this step: "Reboot, you should boot normally this time because no drivers are installed but the graphics settings will be poor" And windows 7 started installing the WDDM 1.1 drivers. i rebooted and everything works fine for now. And know what?

I tried and updates my motherboard's BIOS and now everything works perfect !