Try right-clicking on "My Computer", and clicking "Manage". Then click "Manage". Click on "Disk Management", and see if it shows up there. It might be that Windows cannot assign it a drive letter for whatever reason. Is it a brand new external hard drive?
no its not firewire, well its not showing up in disk Mngment but I do see it as disk 1 "unallocated" im assuming it needs to be reformatted how do I go about doin this. cant remember..