Yes you can: follow this link. Or, change the size of the partition using space from the other partition. Gparted will do the job and its free, just do a search for it.
http://computeradvice.mikebinns.net/setVirtualMemory.php#
Best bet though for a faster system is to increase the size of your RAM.
I see you have an XP OS that is on SP1, upgrade it to SP3 or it will be wide open to infection.