Disabling Hibernation and the Hiberfil.sys file In XP
Disabling hibernation shouldn't cause any problems, and it will eliminate the need for the Hiberfil.sys file, which will be about the same size as the amount of RAM you have. The Hibernation file actually contains the full contents of your RAM and key CPU registers, plus some housekeeping data, as of the moment the hibernation system kicks in. When you have a lot of RAM, the Hibernation file can eat a large ampunt of disk space.

Hibernation is best for slow systems and on portables (to save power). If you have a reasonably current desktop PC, hibernations offers few real benefits, and does use a large chunk of  disk space.
Plus, doing a clean boot instead of resuming a previous, hibernation-saved session, lets you avoid some potential complications that can arise from out-of-date network addresses and such.
If you don't plan to use it, you may as well disable it.
Here's how:
1. Go to Start> Settings> Control Panel.
2. Select the Power Options Icon
3. Click on the Hibernation icon
4. Uncheck Enable Hibernation