It is on the underside of the motherboard. You will have to disassemble the whole laptop.
No, removing the bios battery on a laptop will not reset bios settings.
According to a Google search, Dell makes Vostro Computers.
Most likely the battery failed, even so it shows that there is something left. If the battery is working properly, you have problem with switching circuit which is responsible for power source (battery or power adapter). If second happened you will have to send it to Dell to fix.
No, for the slim tower Dell Vostro 200, you will need a specified PATX psu. Only the mini tower can accommodate mATX-ATX psu's.
dell
Yes it has a inbuilt webcam, but I don't know how to use it.
i would like to have xxx with your grandmother sucker
i3 is better i think
Yes, it is on the front left side.
Go into device manger and see if it is seeing thel camera, and if not reinstall the driver from the dell website.
Yes, there is a microphone in the Dell Vostro 1550. I would recommend buying a newer model, because the 1550 is seriously outdated.