Have you tried clearing all your temp internet files, defragging the
HD and doing a disc clean up, these are the first things to try.
Does it run at start up or is it stopped..? If it's stopped at start
up then when you access it, it will take longer to load as it got to
load into RAM.
Try clicking start, in the run bar type
msconfig click OK a screen will pop up
looking at the far right you'll see a start up tab click this to open
and see if MS Office box is ticked in which case when you boot up it
will load into RAM, if not tick the box so that it loads into RAM
tick ok and then reboot.
When you make any changes to this window you'll get a window popping
up that says "Changes have been made" every time you boot,
simply tick the box that say's don't show this again and it'll go
away.
If you don't use Messenger untick the box that says
[b:d9393d23e8]msmsgs[/b:d9393d23e8] while your in there as this runs
all the time in the background even when not on-line, it's been known
to hog the computer.
Always advise making any changes to these to keep a log so you can
revert back at any time, not saying any this is your problem though
but to me seems a logical thing to try.
All sorts of 'nasties lurking these day's have you checked for spyware
and viruses that may be hogging in the background.
Davy