What does your DCin / Battery Indicator light (1st light from left, group of 3 lights on right front edge of laptop) show when you have the power adapter connected and switched ON?
Amber = charging
White = Fully charged
No light = Battery not charging or other condition
If amber light is on check battery status either by clicking the battery icon on the Taskbar or
via the Battery Status in the Windows Mobility Center window.
If low allow time for battery to charge.
It will charge quicker if you shut down the PC but leave the power adapter connected and ON. Check that the amber light is still ON when you do this. Light should change to White when fully charged. If it never changes it is either a faulty battery or faulty battery charging circuit
If no light it is either a faulty battery or faulty battery charging circuit
Check that the battery is installed properly - consult user manual if unsure