oops - just seen ccleaner in your list
everything sounds OK
possibly running ccleaner too often - monthly or even longer should be ok - same for fefrag (and don't forget to check for errors)
possibly your scanners - could be corrupt driver
or even something trying to run that is actually ininstalled
finally some network errors can take 30 min to fail ...
any old shares or connections?
my personal fave is
http://www.mlin.net/StartupCPL.shtml
if you decide to give it a go - BE CAREFUL
and remember you can re-enable in safe mode!!
it's very time consuming - but only disable 1 at-a-time
and don't delete anything till certain
this is a recent install - not much added yet
http://i33.tinypic.com/34pcdqq.jpg
so it should give you some idea of what it should look like
your only other optionis to use the restore disks and reinstall to factory default
you'll need to back everything up first