Get more memory.
I'm really out of money, and it's only like 220MB ram. This is really needed?
Spend less on Pro software if you don't have the money, use consumer software instead. I guess the rest of your system is also below requirements.
Honestly, if you are planning on doing HD editing with PPro CS5, you need a substantially powerful computer.
I can't imagine trying to run PPro on 2 GB RAM.
The CS5 version is optomized for 12-16 GB RAM to get full performance and I would be very hesitant to even try it on less than 6 GB.
Harm's advice is solid- if you can't obtain the necessary hardware, you will likely be very, very disappointed with CS5.