Check to see if you computer has a second hard disk drive bay. If it does you can add a second drive. If not and you have a CD drive you could possibly remove it, get a HDD caddy, and install a second drive. You could always try and external drive if neither of the aforementioned options is available to you. Another option is to buy a larger storage capacity drive and do a fresh install of everything. A last option could be to clone the current drive to a larger capacity one.