Step 1: Internet Browsing
1. Erase all Internet browsing history
2. Clear Google search history
3. Take care of downloaded files (Next Step)
Erase all Internet browsing history
To wipe the history, go to Tools > Internet Options. A new window should pop up. Click the "Delete..." button. Another window should pop up. Click the "Delete History..." button. Now sit back and watch the magic!
Clear Google search history
!!WARNING!! This step can only be done if the computer has the Google tool bar installed. If it doesn't, I recommend not using Google, because it saves your searches.
To clear the Google search history, goto your Google search tool bar and click the little down-arrow. Then click "Click History". You're Done! (Well, with this step at least)
Step 2: Take Care of Downloaded Files
Whatever it is that you downloaded, you probably want to run it/open it. That's all fine. Once you're done using the file(s), You have to delete the file(s). You're not done yet. Open the recycle bin and click "Empty the Recycle Bin". Now your done. (Almost)
Step 3: Take Care of Files. Again.
Step 4: Finish Up
1. Cleared Internet Browsing History
2. Deleted and cleared all unwanted files
3. Cleared the Google history (If possible)
4. Cleared recent files
You're all done! Now go out and f&@# up your friends laptop!