WOW you may be able to free up around 700MB by copying them to your ipod and then deleting them. You really need to Backup your Data and uninstall anything that is not being used. I would suggest to have at least 17% of your drive free before trying to defragment. If it gets to 15% and under it may not work.
Free Up Wasted Space
Cleaner: Windows
When you first open Ccleaner you will have an option to Analyze or Run Cleaner, after checking the left Pane and making your choices. Delete all Temp Files. If you scroll down you will see a greyed out box that has Advanced next to it. Left click on it and keep pressing OK to all of the responses. I normally Untick Windows Log Files and Memory Dumps as they may come in handy.
You don't have to install all of the add ons or shortcuts just the one to the Desktop.
http://www.ccleaner.com/download
Clean up the Registry
CCleaner can be used to tidy up your Registry. Backup the Registry as you go along, rescan again and again saving as you go until there are no errors left.
Defragment Your Computer
1. Open My Computer, right-click Local Disk, and then click Properties.
2. On the Tools tab, click Defragment Now. The Disk Defragmenter opens.
3. Click your first hard disk, and then click Defragment.
4. If you have more than one hard disk, repeat this process for each hard disk listed starting at Step 3.
