I will fill the details in later.

• ccleanup.com
• defragment the hard drive
• Reduce Internet Explorer temporary files size
• Remove startup programs from registry
• Run a spyware remover or two.
• Look and see how much memory you are using when just after the computer boots up and has finished starting everything. If you are using more than two-thirds of your memory you should add more. Especially if multiple people use it, you do a lot of music stuff or play games.