said by stevenros:
May be u are right. But if u look at »www.apple.com/macosx/specs.html its recommended by Apple it self that 2GB RAM is sufficient for Mac Lion.
Do you have any other solution please. Please mind the investment part of suggestion
Well, it is "sufficient" in that your system does run, right? You say you are editing large media files. That is generally a use case where more RAM is indicated. 2 gigs of RAM, or even 4, is not going to set you back all that much.