Most accumulated files are temporary internet files-so open the explorer-choose tools,then delete your temp internet files and cookies if desired.
With winMe you can delete your temp files found in the windows folder manually.
Theres always more than one way to skin a cat.
You could try extracting the cleanup executable from your windows cd to your windows folder though my guess is that your problem resides in the windows registry.
When In Doubt-Format and start over