Hi Norm69

Perhaps go into msconfig, and under the start up tab, uncheck any unneccessary things from running at start up.
(start...run...type in: msconfig click ok...and check under the start up tab)
Here are two links to tell you what those items are:

Msconfig entries
and
More of the same
Recent and updated virus scan?
If not....Maybe start with one of the free online virus scanners then?

Grisoft
Housecall
Panda
Symantec

And for Trojans.....might I suggest:
Tauscan


Checked for Spyware ?

Dusted your computer out lately with canned air?

Daizy