You could delete them but unless you are running out of hard drive space (my computer runs fine with less than 5% hd space free) there isnt any reason to.
internet speed can be various reasons, I assume you are using firewall and antivirus as it could be caused maliciously. alternativly it can be caused by other things you are doing (downloading especially torrents), and some of the more popular websites are slow when busy, or could be your provider is throttling your service at the times you use it (try very early morning and see if it makes a difference)
computer running slow is a harder one to work out the cause of, when you say load you mean from turning on or when programs are used? if turning on then its a problem with the windows install, or programs you are running at startup (i.e what is in the system tray). Or there is a possibility it is a hardware fault, this would show with the computer being slow with games, and opening new applications.
the easyist (well possibly) way to deal is to completely reinstall windows if it is caused by the software, hardware problems would need more info in order to help you.
if you could report back with as much info on how and when the slowdowns happen then possibly we can further help with the problem
R, May 2010
