Problem after a crash

Hi, I'm not sure if thus is the right place to ask about this, but I could really use some help. A few weeks ago I noticed that my laptop was running slowly, but I ignored it until recently when the speed seems to start decreasing more and more rapidly. This climaxed the other night when my laptop from completely while I was browsing. I forced a shutdown after it seemed to me that waiting it out would do no good, but when I tried to boot up again, it seemed very slow to start, and each time I would her past the hp screen, there would be a blue screen with a sad face that said there was an Eurobond that it would try again. It tried to run this recovery/repair thing after a few tries but it just sat at a lit black screen, so I left it at that screen overnight to see if it would fix itself. In the morning, it was still a lit black screen, so I forced a shutdown again, and tried to start again. This time was more aucveaful; I got past the hp screen, and to a coloured screen that said it was applying updates. This was all done very slowly, and after several hours I was able to get back to my desktop screen, though everything is running slowly: it literally takes an hour to open a window. My current plan of action is to use a key finding tool to find my product key in the registry, and then to try a system restore. I came hear to ask if any of you technologically enlightened people had any other ideas for me, in case mline don't work.

Also, I was wondering if there were any kind of software I could buy to prevent something like this happening in the fffuture. I currently use free avg as my virus protection, but I'm not really sure what caused this problem.

I don't have acchess to all my laptops specifications, but here are the ones I know:
Windows 8.1
Envy dv6-7250ca
Intel core i7-3630QM processor
8192MB DDR3 SDRAM
750.gb hard drive
The laptop says HP on the back

I'm not very tech-savvy, but I appreciate any help you might have. Thanks!