To turn off unneeded programs that run in the background: Start > Run > type Msconfig > click OK. in the window that opens click Startup tab. uncheck anything you don't want at startup. click Apply. click Services tab & turn off anything you don't want running, click Apply, click OK, do the required restart. When Windows comes up you'll get a window about configuration utility, checkmark the box click OK.
Get the free Eusing Registry Cleaner
http://www.pcworld.com/downloads/file/fid,64953-page,1-c,systemresourcestuneup/description.html
The 1st time I ran it, it removed over 1100 useless entries. I run it weekly & it removes another 50-60 each time
Get the free CCleaner, it does a better job than Disk Cleanup
http://www.pcworld.com/downloads/file/fid,24149-page,1-c,systemresourcestuneup/description.html
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