Ok, for all those people who have Microsoft Windows computers that run slowly and produce pop-up advertisements all the time, I'm going to do you a big favor and tell you what you need to do. The best part: ALL OF THESE SOLUTIONS ARE FREE!
1) Check your hard drive
Open a Command Prompt (click Start, Run, and type "cmd" then hit Enter) and run "chkdsk c: /f" to check for file errors on your hard drive.
2) Run Windows Update
Go to Start, Programs, and click the Windows Update icon. You'll need to be connected to the Internet for it to work. Make sure you download all the Critical Updates, regardless of how long it will take!
...