Can I install windows vista on an external hard disc

[bobmac322]

Hi I have a vista laptop with a new hard disc fitted and my cd drive isn't detected by my motherboard and can't get my external cd drive to be recognised can I use my desktop pc to install windows to an external hard drive first then fit it back into my laptop

 

[hang-the-9]

No you can't. Will not boot right if at all. Is the external drive setup as a boot device in the BIOS?