Various Computer Issues

How do I go about fixing the installer if it is corrupted?

I'll post the error report once I get it working. It's currently not detecting my wifi network or anything -.-"

Alright, basically did a system restore and it seemed okay until the computer just stopped responding. Restarted and got the same error message as before; I opened it and got the specific details of the log as you asked:

 Spoiler

I'm pretty much at a loss here. I have no idea what I am looking at or what to do with it. I've tried googling a few things on how to fix the installer, but most of them seem outdated (granted this computer is three some odd years old, so I guess anything related to it will be outdated). I appreciate your help =/

Ugh, just another thing to add: my sound isn't working. I went to my device manager and all of my drivers are installed, but when I click on the speaker in my task bar it tells me:

 Spoiler

And for some reason my Task Bar/Start Menu keep switching from the standard blue Windows XP, to the Classic. Any thoughts on why? ;-;