If the system is slow overall it may just indicate the current system needs some TLC.
Try, in order:
Uninstall any programs you don't use, then sweep through the drive to delete any remaining files/folders left behind by the uninstall.
Delete any unwanted files; Photos, movies, old projects.
Move any file folders off the desktop, 'copy and paste' them into the 'C' drive.
Run the Windows disk cleanup utility to clear out the garbage.
Download and install Ccleaner from here: http://www.piriform.com/ then run it to fully clear out the HDD.
Still using Ccleaner, run its registry cleanup and SAVE the registry when prompted.
Fully power down the system then restart.
Run the Windows Defragmenter tool on the 'C' drive.
Reboot.
Done.