Have you ever defraged the hard drive?
Do you know how to do a COLD BOOT?
If you always shut down your computer using the 'Hibernate' feature in Windows you should use the the 'Disc Defragmenter' and 'Shut down' your machine periodically, to de-clutter (bit like dusting the furniture - the dust just arrives you don't know from where it just does
)
Edit Does dragging and dropping the icon-shortcut (left mouse button hold in / on) to the Recycle bin freeze Vista?
< left click
once on 'My Computer'
< right click on 'My Computer' from the drop down menu
< left click 'Manage'
< open the 'Storage' profile and from the tree menu select 'Disk Defragmenter' ( see attached .bmp file )
< select the main HDD should be 'SYSTEM (C: )'
< click on 'Analyse' and the colored bar should appear after a moment
< click 'Defragment' and the process is initiated and running (you will need 15% free space on the drive for it to "Run")
In the very bottom bar of the screen it will give you a running progress. When this reaches 100% the program will give a 'View Report' option you can save this, choose to store it where you will remember where it is. Close the screen and at this point I recommend shutting the computer down completely
so it might be worthwhile begging this when you are about to leave the computer for the day.