well, im trying to use this old computer

Intel Pentium 3
128 MB of ram
18.5 Gig HDD

it's not like im trying to 5-box on it, but it is extremely lackluster
since i quit WoW, i've been playing a lot of Runescape because it's free and actually pretty fun

BUT.... I downloaded the client for runescape and when i run it, it takes up 99% of my proccessor...

this seems very wierd and i was wondering if there was a way to not make it use so much memory without buying more RAM or anything because i don't think i can even buy any RAM for this computer