I have had my Toshiba Satellite Pro with Windows XP for a good few years now. She has always worked like a gem and has given me no problems until a few weeks ago.

A few weeks ago I was downloading a program and with it came the very unwanted and unliked "Antivir Solutions" virus. I did everything I could to get rid of this disaster (thanks to the help of support forums) and I think I managed to get rid of it, but ever since then my computer has not been the same.

I was having trouble downloading a PDF document a few days ago and it froze so I tried to restart which caused the computer to have a hissy fit, deleting my user account which meant I had to set all that up again from scratch. And, now, the computer takes a good 45 minutes from the time you press the "ON" button to when it is ready to start working. Not to mention, it takes a good 10 minutes each time you click an icon for the program to actually start..

I have tried defragmenting the system and have tried uninstalling unused programs to speed the computer up, but it hasn't worked.
I have also run several antivirus programs (such as Norton, AVG and Microsoft Security Essentials) to make sure I have no nasties messing me up, but they come up clean.

May I also add- The sound is messed up also. Whether I use the inbuilt speakers or external speakers the sound is disjointed and broken. As is any Video I play.

I just don't know what to do.
I cannot really afford a new computer, but I need my computer to be reliable. I use my computer for 12 out of the 24 hours in each day...
What can I do?