Should be very quick.
System File Check; click here
Disk check; click here
Complete anti-virus and anti-spyware scan. Free ones here (don't install more than one AV program at a time) click here
Recommended anti-spyware; AVG and SpywareTerminator, Superantispyware. You can have more than one anti-spyware product installed with no problems, but disable all but one `resident` scanner (anything which monitors your system in realtime)
Online AV scan here; click here