Connecting a USB HD with Windows on it to my PC - will it cause problems on the PC?

[cyberia]

I got a new PC with a fresh Windows installation on it. I want to use the HD from my old PC as a USB drive for additional storage on the new one.

If I leave the old HD unformated, with all the data and software on it including the old Windows installation, will it confuse my new PC's Windows?

Thanks.

 

[Fullmetal Chocobo]

No. It matters which drive is set to boot (think fdisk), or the system disk. I do that many times when I'm working on someones computer, and they need to backup their stuff.
Tas.

 

[cyberia]

Thanks!