BSOD NVSTOR64.sys irql not less ot equal to zero

Its been a week I am struggling with Blue Screen on my new upgraded Windows Vista system. It worked fine over a month after installation but since past 1 week ever now and then I keep getting the following error with BSOD:

driver_irql_not_less_or_equal

nvstor64.sys - address fffff9800053cb0a base at fffff98000537000, datestamp 458d544e

collecting data for crash dump ...
initializing disk for crash dump ...

Tried several things to figure out the cause but no success. Hope anyone of you can help me with this. Thank you in advance.

According to the error "nvstor64.sys - address fffff9800053cb0a base at ....." the problem is with Video Card driver and most probably with nVidia drivers. Simply uninstall the drivers, restart the system and install the most recent drivers downloaded from nVidia's official website.

This will fix the problem for sure.

I appreciated your help Janos. As per your suggestion i downloaded the latest drivers for my Video card, uninstalled older version, restarted and installed the new drivers. After 10 minutes of doing the same i got again a Blue screen but this time the error was different. Now it says:

"A clock interrupt was not received on a secondary processor within the allocated time interval"

Now what happened to the system? Should i go back to my XP where i never had any such problem in past 5 years?

Somewhere the problem is with your Video card itself. Most probably the GPU is not able to send or sent corrupted information to the CPU, or information that could not be read or simply was not received by one of the cores on what appears to be a system with a dual core processor. Nonetheless, the fault appears to be an issue with the graphics card, you need to check for the latest Vista Compatible drivers for your card.

Re: A clock interrupt was not received on a secondary processor within

This is a defective core on a multi-core CPU message. Several people on other forums have fixed this by getting their CPU replaced. It will usually happen randomly every time your computer happens to hit on, or try to use that one defective core. At other times, while using or stressing only core 0, it will probably run just fine. Sometimes you can turn off the defective core in your BIOS, if you run a program that will tell you which core it is. You have Core 0 & 1 in a Dual Core CPU, & Core 0, 1, 2, & 3 in a 4 Core System. If you give them your credit card number (AMD) they may be willing to send you a new CPU first, then you send the defective one back. If AMD does not get the defective one back, or determines that the one you sent is not defective, they may charge your credit card. Google CPU-Z or other programs to stress test your CPU first.

IMHO
isepiq