acer travelmate 4000 heats up

The term 'hot' is very relative. Have you tried to check how high the temp gets? Does the laptop shut off after minutes/hours of use?

I would be online for 20 minutes, then the labtop heats up. when it becomes very hot, it would shut down.

I would then let it cool down before I would continue checking for virus.

or power the labtop back on.

I don't know where to check the temp of the labtop.

Have you done any cleaning of the vents/heatsink? Use a can of compressed air to blow out the dust that may have accumulated in time (Best if you can open the laptop and clean the insides and reapply thermal compound).

ok,
I will clean inside the laptop and reapply the heatsink. I have some thermal past .

will try it..