Hi, I recently bought a 160GB hdd and I'm having some major problems with it. The reason for getting this external HDD was to replace my old laptop's spoilt internal HDD. I am able to install my OS on the external HDD however, when i try to start up my laptop using the OS from the external HDD, there is this stop error message that says: "Windows could not be started up, it has been shut down to prevent damage on your computer. If this the first time you are seeing this message, please restart computer. However, if this is not your first time seeing this message, please check your hard drive....." It is a blue screen and nothing goes on. The com just hangs itself.

I would appreciate it if anyone could guide me on how i should deal with this problem. Thanks

First, why didn't you just replace the internal drive and install Windows.
You can install Windows on the external drive but when you restart, it can't find the drive (USB drive?). Go into your BIOS and see if there is an option to boot from an external/USB drive.
If the BIOS is on the harddrive (seperate partition) as some laptop manufacturers do, I think you need an internal drive.
Then again maybe the laptop is too old to recognize a drive this big.