Runs very slow,has been repaired twice for viruses

Try to add more ram. If you have sufficient ram optimize your startup programms and background services. If It also not Then Install updated Quick heal OR Mcafee And Scan Whole Computer For Malwares...

If you have anti virus software on the machine, update it and run the program to scan for virus or spyware etc If you havent got anti virus there are many good that dont cost that much or FREE ones like AVG (you can only run ONE anti virus program at any one time on your machine, as i say if you have anti virus update it... if its a trial that you dont wish to purchase then you need to unistall that software before you install any other)
http://free.avg.com/gb-en/homepage
and additional programs like spybot, again free (can donate if you wish too) which you can install and run too
http://www.safer-networking.org/en/download/

Have you tried a Disk Cleanup? This can often cause computers to run slowly. Look under Start>All Programs>Accessories>System Tools.