Can you create a second user and then logon as the new user and see if it's still slow? That would eliminate a messed up user profile.
If that doesn't help then:
Get Process Explorer
https://live.sysinte...com/procexp.exe
Save it to your desktop then run it (Vista or Win7+ - right click and Run As Administrator).
View, Select Column, check Verified Signer, OK
Options, Verify Image Signatures
Click twice on the CPU column header to sort things by CPU usage with the big hitters at the top.
Wait a full minute then:
File, Save As, Save. Note the file name. Open the file on your desktop and copy and paste the text to a reply.