Hello everybody,

I have a problem which with my PC has been persisting for several months:
Every 2-3 days it freezes - the cursor turns into a circle, and although the mouse is movable, I cannot close any program. Occasionally (not every time this happens) screen goes black as well. So the only choice I have is to reboot the system by pressing the power switch.

If I reboot PC, it does not load. I have to run drivers and utilities CD (which came with the PC) and after running the system test it shows "all is OK!". I reboot PC and everything works until the next time (in 2-3 days).
I should mention that this situation started to show up when my graphic card had failed a few months ago and I started to use VGA input on the motherboard.

I was told that it's like to be the video card problem, but before I buy a replacement video card I would like to ask you -

1. How can I check there are no other hardware problems with my PC?

2. Is there any diagnostic software (preferably free) that I can run to make sure it's the video card problem?

Any suggestions are greatly appreciated
Thank you in advance

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My PC specs are as follows:
PC model: Dell Inspiron 530s (slim)
Processor: Intel(R) Core(TM)2 Duo E6750 : 2.66 GHz
Motherboard: Intel(R) G33/G31 Express Chipset Family
Graphic card: ATI Radeon HD 2400 XT 256 Mb half height
RAM: 3Gb
HD space: 500 Gb (over 160 GB free)

Operating System: Vindows Vista Home edition