OS 10.3 - multiple problems - software update & disk mounting

I was trying to mount a disk image, and it gave me an error, I found this quite odd, so I tried mounting another disk, same thing. After a quick google search, I found out that this is a known problem. Here is the solution I found...

This is somewhat outdated, but i'm running OS 10.3.3 right now (my dad didnt want me installing any new ones becuase it changed settings of his apps *rolls eyes*) but due to this problem, I decided it would be okay. I went to software update, started installing the 10.3.9 update and corresponding security update, and coming back to the computer about an hour later, software update had crashed. So, I tried just downloading the 10.3.9 combo update, download went fine, but attempting to install it gave me trouble, it got to 99% then just stopped installing and said there were problems installing.

So, I cant mount disk images, and I cant update my OS from a problem installing. I dont have 10.3 install cd's at home, where my dad works, they bought a family pack and had a licence or two left over, so we just used that.

I think I would be able to borrow those and then reformat the HDD and hope that works, but it'll be a big hassle, i've also run out of blank cd's, but if that's what i've gotta do, so be it. I think they might actually have 10.4 install cd licences left over, so maybe get my hands on that

Thanks in advance
Matt


*edit* comp is a g3/500mhz/128mb ram/20gb HDD if it makes any difference at all, yeah, I know, needs some updating..