Weird Problem

Last night i bought a one year licence for Anti Virus 2008

On my desktop I dont have a problem but on my laptop it crashes when i try to scan.

I click on one of the scan optopns and suddenly the computer goes really slow and i end up haveing to do a hard reset.. yet however if i right click a folder and scan from the dropdown list It will scan fine abd after that quick scan options seam to function till the next reboot.

My laptop is running vista home premium the same as my desktop is.

This is really weird because the trial worked fine..

Thanks