Vista Reinstall issue

[qandaseeker]

hi, i have reinstalled windows vista on my PC.
Every 10-15mins the computer crashes for like 1 minute!
This never happened before! When i restart the computer, a message says 'windows defender couldn't start'.

The only program i have downloaded is McAfee software.

please help me.

thanks

(Update)

Ive deleted McAfee and installed AVG, but its the same problem.

Thanks

[ACtheTROLL]

do it all again

download your virus protection to a usb stick
disconnet the net
reinstall vista
switch off auto update ....
install virus scanner
let machine run ....

connect net
let machine run ....

install updates in blocks
let machine run ....

keep going untill its all done
install a

[qandaseeker]

i have reinstalled it but the problem is still here......!

Please can you help me.

cheers