What to upgrade for this computer to reduce issues and lagginess?

My computer has been rather slow on me. Its actually supposed to be working just fine.However i always recieve error messages like virtual memory too low, some weird error messages, and is always suffering from slow start up. Any tips? Ive tried going to yahoo answers and do what its been said. but recently, problems start occuring. i even have to choose which device to boot? i dont know whats that.

i have the AVG free anti virus , cc cleaner, and spyware terminator.

my Avg takes 2hours to complete a full scan of my computer.

And iam rather interested in playing the game counter strike, i do have it on my computer, despite the low ping/latency , im still suffering from sever lagginess. Would adding my RAM help that issue?

Plus the air surrounding my CPU is always very warm, is there any way i can do something about that?

have this processor : hp pavilion w1184d

3.00 GHZ. 256MB RAM Radeon x300 series

i dont really have much money, so pls aid me with that in mind. (:

What to upgrade for this computer to reduce issues and lagginess?antivirus scan

Using a registry cleaner can clean up your computer and then make your computer faster,Why?the reason is that there may be some regsitry errors and remnant,corrupt files and temp files in your computer to cause ''computer slow''.

Everytime you install and uninstall software on your computer and surfing online you create junk in the computer registry.over time, the registry can grow to enormous proportions, especially if the various programs you've installed do not do a good job of deleting and/or updating it's Registry entries.You need to scan and clean your computer with registry cleaner to make it fast.Good Regisry Cleaner will improve your computer and Internet performance dramatically!It even can speed up your computer by 300% or more!