Worth a try

But it can take a while.  The Independent  advises:

First, run a disk clean-up (Start>programs>accessories>system tools) which will remove temporary files and all sorts of other junk from your hard drive.
Secondly, disable any programmes you don't need that automatically start when your computer is switched on (start>programmes>startup).
Finally defrag your hard disk (start>programs>accessories>system tools>disk defragmenter). This will take several hours – you may want to leave it overnight – but it will speed up performance by more logically storing data on your hard drive.
If you are running a Mac make sure to clean up your dashboard as it eats up your machine's memory. Fire up the activity monitor (applications folder>utilities>activity monitor), if you see a lot of dashboard applications high up the list, consider disabling any that you don't absolutely need.