What is your laptop? If you can find some sort of document about it (like if you make a google search for the model), you can find out if you can upgrade it.
Quote: "Windows 7...... Nah, I'm happy with xp (the vista CD is my dads). But i was thinking about installing Linux on a portable hard drive and i was wondering, what ram would that need? And the price? I was looking on ebay and found Linux xp for £3.00, is Linux xp good?
Then i thought about my usb ports (they aren't very good) then i saw something about running Linux from a CD?!? Could that work?"
Have not tried that version of Linux, but in my experience some dists can be very good, others very bad, it all depend on what you want and what hardware you have (lets face it, you can find the most user-friendly OS there is, but without drivers you won´t be able to use it).
A live-CD, running Linux from the CD, has its uses, but casual use is not one of them. Would rather recommend using a virtual machine (like Virtual Box, or VMWare, but then you would not be able to use 3d stuff), or maybe wubi (which is limited to Ubuntu and maybe some of its side-tracks, such as Xubuntu). A dual boot can also work, but is not recommended if you are not willing to experiment on the computer in question.
And as for RAM requierments, it depends. Some can run on as low as 32 mb ram, others require more. Have not seen anyone that is as demanding as Vista, though (not saying it does not exist, just that I have not seen it).
"Operator! Give me the number for 911!"
- Homer J. Simpson