Arti is correct...you need to talk to a hardware "Professional" about what you can and cannot do to your current laptop. I am a computer geek, but I know a lot more about software than I do about hardware. One thing you can do yourself is go to website for your laptop manufacturer and find out what the maximum amount of RAM you can add to your machine. For my HP laptop, the most I could have is 1 GIG. Memory is, in general, not terribly expensive.
My laptop is 2+ years old and I run PS 7 on it. I upgraded my memory to 1 Gig and that helped the most. I also got an external hard drive ( 160 gig, I think). I have all my scrapping stuff, including pictures loaded on there. It's a heavy beast, but it sure beats having a full hard drive
HTH~