Ubuntu really slow

My Toshiba Satellite Pro is still running on XP as I can't yet afford to buy a better OS.

Unfortunately I am unable to connect to the internet on this laptop so I installed Ubuntu as a fix.

I find Ubuntu to be very slow to operate and although there are fixes suggested on the web, these are not as straight forward as I had hoped.

I'v only got 750Mb of RAM installed but even this was sufficient to run XP when I could get on the internet.

Can anyone offer a solution to the slow running of Ubuntu or suggest an alternative free OS?

Thanks