Help! After installing video driver display goes dead

[eflat]

The card works okay before I install the driver.

Once I install the driver the card works fine but as soon as the windows screen loads everything goes black.

The video card is a Matrox G450 PCI. However I had the exact same problem when I tried to install a different PCI video card so I know it has something to do with the computer and not the card. Any ideas?

 

[eflat]

Anyone? Should I ask this in general hardware?

 

[winr]

Was the PC working ok and then you changed cards and it started acting up.

or

Are you trouble shooting a PC that already has a problem.

 

[eflat]

It was working great until I tried to switch cards. If I switch back to the onboard video it works fine again. If I check the status of the new video card under the device manager it says it has the latest driver and is working properly..

 

[eflat]

Whaa it still won't work!