Running Windows with LINUX on an external hard-drive.
I recently attempted to install a LINUX OS onto an external hard drive (with the intention of using LINUX alongside Windows. The install failed and, mainly due to me not knowing enough about what I was doing, it wouldn't boot anything. I've had Windows repaired by someone from a computer shop, but was told by them that it would be inadvisable to plug in the external hard drive (containing [?] the LINUX OS).
If I plug this external hard drive back into the computer, will it wreck the system, or will I be able to format the external hard drive to be able to use it with Windows again? What else should I know before doing this, what conflicts could it cause etc...?
I don't intend to use LINUX again (not without finding out what I'm doing first) - I just want to be able to format this external hard drive to use with Windows.