Hi,
First sorry for my english... I don't use it usually...
For obtain more space you have differents options before to format discs. Really format all the discs are a good solution, but can be "expensive" too, because you have to remember to save all your documents, videos, mp3, pictures, files of exchange (if you have...).. Save your profile (this is locatted in the 'Documents and Settings' folder whith your name... remember all yours passwords (introduced in web pages...). I don't know why, but is very easy and usual, that people lost some information
Really if your system works fine and you only need free space.... you don't need format your discs...
Before format the disks I will try with other things... For example:
- Move all your documents, photos, etc... into your unit D
- If you use applications how emule... Close it. Move the folder with the temporals files into your unit D. Open the application and change the configuration... Specify the new path for the temporal files (now in unit D). Is very important this temporal files musn't to be allocated in your unit C because can to drown the System (this need free space...)
- If you are using some program, which use very much space on disc C. You can uninstall it, and re-install this program specifying a new path into your unit D.
When you have obtained more free space in your unit C... Is when you must to do a deframentation in your unit C.
If you really need format your disc.... You can move all your data allocated in the unit C to the unit D... And format only the unit C....
I have explained well??
See you... and good luck!