I am trying to free up space on my c dri...

Yes you can. Your OS needs to be Win XP Professional in this case and needs to be NTFS.
This is called 'Mount Drive'.
A Mounted Drive is a drive that is mapped to an empty folder on a volume that uses the NTFS file system. Mounted drives function as any other drives, but they are assigned drive paths instead of drive letters. When you view a mounted drive in Windows Explorer, it appears as a drive icon in the path in which it is mounted.

You can also use mounted drives when you need additional storage space on a volume. If you map a folder on that volume to another volume with available disk space (for example, 20 gigabytes), you extend the storage space of the volume by 20 gigabytes (GB).

This is how to.... loadTOCNode(2, 'moreinformation');

1. Click Start, click Run, and then type compmgmt.msc in the Open box.
2. In the left pane, click Disk Management.
3. Right-click the partition or volume that you want to mount, and then click Change Drive Letter and Paths.
4. Click Add.
5. Click Mount in the following empty NTFS folder (if it is not already selected), and then use one of the following steps:
   • Type the path to an empty folder on an NTFS volume, and then click OK.
   • Click Browse, locate the empty NTFS folder, click OK, and then click OK.
   • If you have not yet created an empty folder, click Browse, click New Folder to create an empty folder on an NTFS volume, type a name for the new folder (eg. Games), click OK, and then click OK.
6. Quit the Disk Management snap-in

I hope this has helped.