AVG won't uninstall, laptop can't boot up

Hello,

I have a problem with my laptop, it won't boot up. Sometimes it won't even start in safe mode, when it does that it is always stuck on avgidsha.sys. But sometimes it will start in safe mode and I tried to uninstall AVG 2014 via control panel, but avg says it didn't succeed. So I tried it via CMD, this is what I did:
Wmic
Product get name
Product where name="AVG 2014" call uninstall
I then proceeded to press y to continue, afterward I got this message:

Method execution succesfull.
Out of Parameters:
instance of __PARAMETERS
{
ReturnValue = 1603;
};

But after running the product get name avg was still there...

Do you have any suggestions on what to do? Is it safe to just delete or rename the .sys file or would that be devestating?
Is it possible to just delete the avg folder? Or should I do something else?

Thanks in advance,


Augurk1e

Ps. I don't have a great understandig of computers, the only languages I know are CSS/HTM and PHP an JAVA the basics.
Pps. Sorry for my Englisch, I'm from The Netherlands :)