Hello All, I'm Ray and I've an old Packard Bell Desktop originally with windows ME but now with XP Pro crammed in instead (not by me)700Mhz Celeron Processor, 128Mb RAM and two Hard drives C:55Mb D:9.5Mb. Is it possible to install Linux on it at all? As both Debian and Ubuntu seem to indicate a minimum of 250Mb RAM I thought I'd try going the Wubi route but got a 'This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem.' notification, so checked it on my Vista Laptop and it opened fine. Am I just wasting my time with this computer?

With a machine like that you will not be able to run one of the heavy desktop environments (DEs), that are the standard on those distributions. There are some distributions that are specifically aimed at older hardware, like antiX and wattOS, but you should be able to run any distribution with a lightweight DE like LXDE or a simple window manager like IceWM or one of the *boxes.
In comparison to Windows XP that machine should fly with Linux, if you set up it right.

That machine looks like it could run Puppy Linux which boots from CD and runs entirely in ram. It should have no problem running Damn Small Linux (DSL for short) but be warned that DSL is based on an older kernel and can be tough to master if you're new to Linux.

@ glue
You're right! I have a machine set up with macpup, P2/128Mb/2Gb, runs like a rocket!

@ OP

MacPup is a fork of puppy, looks nice and is Puppy, with a E17 jacket, light and pretty!

Thor

By the way, come on in, the water is nice

Thank's to you all for your advice. I've downloaded wary puppy and will try it as soon as I can. Thank's again.