avast has completely RUINED my computer help

[zefsasn]

i downloaded avast and after installing  and restarting, my computer wont work at all i cant log in and its a struggle to get to the homescreeen.
it says loginUI failed and that it couldnt find securtity promts.
i DEMAND to be compensated for this utter BS 

[zefsasn]

running hp with windows 8.1

[Coolmario88]

running hp with windows 8.1

Have you tried to boot into safe mode? I dunno if that though.

[zefsasn]

its ompletely unresponsive apart from displaying the hp logo and the loading txt

[Secondmineboy]

Avast creates a restore point right before it installs. You need to get toget to that option for system restore, then you can reset your computer to that point. But i dont know how to do that on a hp machine.

[AdrianH]

Power off, restart holding down the "Shift " key and tapping fast on F8.

[Pondus]

Did you uninstall your previous used / factory installed AV before installing avast?
Did you run the vendors removal tool to clear any leftover files that may conflict?    http://www.avast.com/en-eu/faq.php?article=AVKB11#artTitle

Hp machines usually comes preinstalled with Norton....

[AdrianH]

Hp machines usually comes preinstalled with Norton....

My thoughts exactly .......... get these in the workshop several times a month