Internet and Computer freezing up and slow

My firefox internet is running slow. Freezes up and when i type or scroll up and down. My processes and performance jumps all over the place. Like from 0% to 33% to 100% and back down. System idle process is using 99% most of the time. Belahzur on GeekPolice told me to upgrade my RAM would help my internet from being slow. I have 480 MB of RAM. Will that help and is there anything else i can try before installing more RAM? Thanks

480 MB of ram is enough to run XP, if you optimize it well. Visit blackviper.com to find out which services you can disable. Use a very light AV like Avira or (even lighter) Panda Cloud, cut down on resident programs where possible.

After I go to blackviper.com where do i go from there to find out which services i can disable?

I have another problem
Why want some sites load up it says unable to connect? I know for a fact these sites work like orbitz.com and priceline.com some sites connect and some don't i don't know why.

help plz