dozydave, if you are interested, a brief explanation of why a low amount of memory can slow your PC down.
Your computer has 256Mb of memory. EVERY program that starts on your PC is placed in that memory.
When Windows starts it takes some of that memory, then if you start your browser it takes a bit more and so on.
Now as long as you dont start too many programs then that 256Mb of memory will never fill up.
But suppose you start another program, and your memory fills up. What is Windows to do ?
What it does is copy the contents of part of that REAL memory out to your hard disk in something it calls VIRTUAL memory.
Now moving data from RAM to hard disk is a slow process (in computer terms) so it is already starting to slow your computer down.
Now suppose Windows needs a bit more RAM memory for something else (maybe you have started Windows Media player).
So it swaps MORE of the contents of memory from RAM out to VIRTUAL memory.
But then it find it needs something that is sitting in VIRTUAL memory in REAL memory, so it copies it from hard disk INTO RAM (again a slow process).
So instead of doing proper work, your computer spends a lot of time copying data from RAM to hard disk and back again, and this slows your PC down.
If you up your memory from 256Mb to 512Mb then your real memory is less likely to fill up, and therefore Windows will not have to keep swaping data back and forth from RAM to hard disk.
But of course any RAM you add above 512Mb is probably never going to be used because you rarely fill up your 512Mb so anything above that is never used.