If it's an old model, chances are Canon won't have updated it.
And how much software do you need ?
I generally ignore the CDs that come with cameras apart from the manual pdf as you can do most of what you need by saving pictures to your drive, downloading via the USB cable or card reader. Then using a program like Photoshop elements (which I admit came on the CD with one of my cameras). There are lots of free programs which do the same job as photoshop -- so have a look at one of the shareware sites like Filehippo etc.