Make sure ur ANTIVIRUS is updated. Then SCAN ur SYS.
U may try this in safe mode (Will be more efficient)
If antivirus is not up to date remove HDD and Connect externally to another sys with a good antivirus, and scan.
When it boots open run and typr MSCONFIG, the press ENTER
the do the following
-go to STARTUP TAB (u'll see a list of progs that run when windows bootup)
-uncheck all execpt ur antivirus.
-apply and click close
-u will be prompted to restart. (do so)
note: this will help a little.
Let me how it goes 4 u.