Ok so iwant to upgrde my pc from 80g to 250g but im not sure if i can buy any old hard drive or it has to be a specific one can any 1 help me out!

what interface is the drive, most likely ATA I assume.

The replacement drive will have to have the same interface, which looks like a wide block with loads of pins, the connector is like a ribbon.

Make sure your motherboards bios can support the larger size, but i dont really see this as a problem

Thanks....but how do i find out if the bios will support a new hd? Im thinking i should just take it into the shop and see what they say...but as you can tell im a neewbie at changing things like this so i dont want to mess it up!

Get advice from your local friendly computer shop.