I would guess that that 1.3Ghz processor is either a very early Pentium 4, or perhaps a Pentium 3. Did P3 go up that high? I know they cracked the Gigahertz barrier
As said, it could be an AMD, too. That should be perfectly fine for internet and word processing stuff. Honestly a 1Ghz processor and 512 ram is fine for that sort of thing. Otherwise it simply is NOT worth putting money into that system. Find a family that would like a simple compute rfor their kids to terrorize, sell it to them for 50 bucks, and think about either saving up and buying a computer to put together, or buying one from the big names and financing it.