system is extremely slow and everything is "not responding"

Click Start - in the search box.
Type
msconfig

Click on the Start Up Tab.
Write down carefully what is listed and post the list here.
Or post a screenshot [s]
http://library.techguy.org/wiki/TSG_...g_a_Screenshot
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AdwCleaner needs to be run until it comes back clean.
Run again - Scan - Clean - post the log file.