Lots of large files?

Starting to become aware of files on my HD as space is getting low, and I see that there are a couple quite large files associated with Parallels. I did have some difficulty during installations and upgrades, so I may have some unneeded files. Can someone indicate if these are all required?

Parallels folder > Microsoft Windows XP 1 (1).pvm [42GB]
Parallels folder > Microsoft Windows XP 1 folder > winxp.hdd [37GB]
/privaye/var/vm/sleepimage [8GB]

I assume that last one is due to hibernation being enabled.

thanks.