@Lockeness - most of what you said is wrong. Time does not make the computer faster. And most issues are not with shoddy battle. At my work computer, with 32GB Ram, running a 3.0GHz, I have 0 lag. Not even a millisecond. It's the computer. 2GB Ram should be fine.
Much more is running then in your tray and dock.
Press CTRL + Alt + DEL, and click on the processes tab. Go onto the CPU column, and find out whats eating up your memory. If it is needed, then don't close it. (Hint: don't close csrss.exe, you'll get blue screen of death) You can find out the name of the task on the 2 columns over.