What exactly is Hijack this, I've seen alot about it but I'm not a techy person and I don't understand it at all (same with the command prompt diagnoses thing)

the internet explore thing still bugs me, and yes I'm positive its iexplore not explore. But I will post reports if you can explain me alittle how to use them ^^; (n00b)
New stuffs been happenin to my computer now, I'm afraid I'm being attacked by a virus

I'll get those windows error report messages like 5 times while I'm on the computer and sometimes they get rid of my explore.exe and my tool bar disappears but now its got rid of my windows xp theme and now I'm stuck with only the classical version, I haven't done a restart yet, i'm sure it will fix it but i don't know whats wrong. Malbytes anti-Malware won't open, even after I uninstall and re-install, so I can't run on that so I've ran Ccleaner and spybot, got rid of the stuff it found but somethings still wrong. Spybot is constantly finding affected files and I would like to know if theres a better protection program I can get :\ sorry lots of text I'm just kinda flabbergasted at the moment

My computers never gone this rotten before...