Hi,
Others mentioned Defrag. I would do it first, in Safe Mode.
Then, download/install the following great, free, cleaner:
http://www.ccleaner.com
This cleaner cleans out cookies (that you don't want to keep), history, URL's, temp file junk, and other junk files. It does a better job of cleaning than Windows.
Then, I would go to Start/Run and type in MSCONFIG, then click on OK
Click on the StartUp tab at top right of that window.
Then, look to the left, scrolling down, and seeing all the programs that start running when you boot up the computer.
You really don't need those referring to "auto update", and may be some more.
Left click on what you don't want starting up, to remove the checkmark, then click on Apply, then OK, and re-boot.
If you have unchecked something you really need, you can always go back and put a checkmark by it.
Best wishes,
fredg