Adding additional RAM is usually the single most important upgrade you can make to improve the performance of a PC, however before spending money upgrading, you should consider a few points:
- What CPU does your notebook have?
If you have an older slower CPU, and your applications are processing intensive, additional RAM may not make a much of a difference in performance.
- What is the speed of the Hard Drive?
Many notebooks have very slow hard drives, often spinning at 5,400 RPM, where desktop drives typically spin at 7,200 RPM. If what you do is very disk intensive, a faster drive, maybe even SSD would be the best upgrade choice.
- What version of the OS are you running?
For general computing, that is word processing, spreadsheets, e-mail and web browsing, 2GB is totally sufficient. If your applications require more horsepower, for example photo/video editing, 4GB would surely help. Unless you are running the 64-bit version of Windows, the operating system will not recognize more than 4GB of RAM.
If you could provide more information about your notebook hardware configuration and what applications you run, we could make a more informed and better recommendation as to what upgrade path would best meet your needs.