Is this an XP machine? Microsoft will stop supporting XP on April 8, 2014. That's a bit more than 3 months away. I do not suggest upgrading any XP machine at this point.
To answer Your question: RAM is only important when You don't have enough, then Your PC slows to a crawl. 2GB is not enough for 90% of modern PCs. So, REEDO_43 is right, it will help quite a bit. While You are at it, if You are going to keep this PC, I would recommend maxing out Your RAM.
ADIMEISER's answer about a SSD is valid as well. I have an old XP box running a Pentium M processor. Adding a 32GB ($20 on CriagsList) SSD as the swap space made a hug difference. You know that time when You have logged on, but Your system is not responding? It disappeared. Of course, using a SSD as Your boot drive (and swap space) will speed it up more, but that's an expensive proposition as it requires that You buy a SSD at least as large as Your boot drive.