NEVER delete anything inside the Windows folder. The three exceptions:
1. Old $NTUNinstall folders
2. Old KBxxxxxx.log files
3. The contents of the Windows\Temp folder
The cache files in your browser are the Temporary Internet Files. They can be cleared from inside IE. In IE8 it's in Tools>Delete browsing history (you can delete more if you want, so think before you click). If you don't have IE8, but IE7 or Firefox, the equivalent won't be too difficult to find, I trust.
Good to ask! Let's hope it helps.
I have been advised that I need to clear cache files to resolve a problem with facebook interaction. Is it safe to just delete these ie H:\WINDOWS\SoftwareDistribution\EventCache. As I dont know about these things I didnt want to do without expert advise.