I take it that you have been doing regular defrags - not just the defrag found in windows, but using O&O Ultimate Defrag Perfectdisk or on of those so that you can get your disc properly arranged using File/Name or similar.
The dual monitor correction can be found in the downloads section of FSInsider and it really works.
The other possibility is that you are suffering from Out of Memory problems and MiltestPilot started a great thread on that using a downloaded utility. Check this forum.
If you didn't save your logbook before you uninstalled and reinstalled it may be lost.
I'm not one of the gurus in this forum, but these things come first to mind. That's without knowing anything about your system.