I just uninstalled my AVG antivirus and then I installed the Avast antivirus. Every time after I installed the Avast and I wanted to boot my computer, I get a black blank screen, so then I have to do a forced shut down (holding the power button down), then I press the power button to boot the computer and it loads my windows vista. I already checked to see if I had any AVG software left and I dont have any. Does anyone know what the problem could be? Am I going to have to switch to another antivirus?
I don’t know if you have tried this - AVG Remover, download tool from here, http://www.grisoft.com/ww.download-tools there is a 32bit and 64 bit windows version, ensure you use the correct one.
Getting a black screen on boot is frequently caused by another AV or remnants remaining (low level drivers, etc.) causing clashes.
If you can boot into safe mode you could try to run that tool from there.
If you can’t run it from there, uninstall avast from safe mode and reboot.
That should hopefully remove one side of any possible clash, run the avg remover tool from normal mode and reboot.