Compaq Presario disk space problem

I was given a Compaq Presario 1200 Series Notebook. I was trying to do a System Save. It attempted to create a hibernation file and reboot, but says there's not enough contiguous free disk space. It keeps going through this process over and over. How can I get to a place to free up disk space? I cannot do any backups as Presario is full but the disk cleanup program only gives the option to delete Office start=up files or recycle Bin = then says deleting these will only create 0 bytes of space. I just keep getting a pop-up every few minutes telling me Presario is full.