During the installation of Windows 7, it kept turning itself off while installation files were being copied into HDD. The bottom of the laptop was getting too hot and I don't hear a fan running. So I had to disconnect the internal battery and ran it on power code to minimize the heat and installation worked.
After installation, it runs fine but the heat is still the problem. Sometime it gets hot enough that I can't hold the bottom.
Could this be a fan problem?
Or what else do I need to check?
This is probably a fan issue, i would also look at power management features in Windows 7. It is possible that with a new install you have disable all power management which means the processor is always running at full power producing higher then expected heat. Set the power settings in windows to power saving. This should help reduce the temperatures until you put the system under load.