replaceing windows XP with ubuntu

Aargh spelling mistake! "replacing" sorry.

I don't think I've got Windows XP now...
I'm still on Windows 7

I'm still on Vista. No sympathy please.

I am still on Windows Vista, so it is only a matter of time before I have the same dilema. Never heard of Unbuntu, what is it?

It's a completely different operating system which is free. It uses the Linux system. I have used it before as it is a good way of utelising an older computer. It is a bit different to use but not so hard. It has an included office suite, etc. and any other programs you need are free too. Their philosophy is that software should be free. Just google it.

another XP user here - on my old and sturdy desktop.
had been toying with the idea of upgrading - firefox runs 'like a dog with no legs' on this machine but I do not need a laptop - computer stays in one spot - so am exploring other options so that I am able to upgrade Windows once XP is no longer supported. .
is Unbuntu memory greedy?

Not at all. That is why it is good on old machines with smaller specifications. I have installed it alongside Windows XP so I can still use my old programs that are compatible with windows but you can get plenty of free programs for ubuntu too. It boots up very quickly and is more efficient. You need a bit of computer know-how to do it but it is worth a try if your machine will be too old to accept a new Windows operating system. Once support goes for XP it will probably be unsafe to go online much longer.

Get windows 8.1, just a short time to get used to it. It is much better than windows 7 or any previous versions, faster and more stable. You will have to learn how to use Ubuntu, which can be a bit mystifying so why not use window s8 and add classic start menu to make it more like what you're used to. I did it for my wife and she will never go back to the other versions as there are lots of apps available for free in windows 8.1.

Ubuntu is the name of the cola I buy for my grandchildren.

The trouble is that older computers with smaller specifications cannot cope with newer operating systems. Ubuntu can give a new lease of life to a less powerful computer. I do use windows 8 on my main computer but I like Ubuntu on my old laptop which would otherwise have been scrapped. I think Ubuntu means "humanity" or something like.

Well done rockgran. I run linux on an old IBM laptop. and also on many other computers in the home.
The computer I am using at the moment is 10 years old and is very nippy.
As rockgran says if you want a program to do something then you can find it on Linux for free and as good as, if not better than microsoft programs.
I run Linux on a raspberry pi and use it to provide a dropbox clone for my household. Just drop a file into "Own cloud" and anyone else in the house can view/use the file!

Thanks for the hint, I have a new computer but my old one has XP and we were going to use it as a spare, so that should work well. I didn't want 8.1, even though I know it has fewer problems than 8, I just wanted a faster bigger memory, I prefer websites to apps so went with 7 for proper computing.