Enter a short description...Can I use an external drive connected to my computer which runs Windows 7 to run Linux? Would this work having Linux on the external drive?
Can I run an external drive on my windows computer when I wish to run Linux?
The answer to both of your answers is "YES". External drives are treated like a regular storage devices, you can install or store anything on them as long you have adequete space.
You can setup dual-boot on your windows 7 externel drive by installing Linux alongside Windows. The space windows occupies will be divided so there is enough space for windows and Linux.
Linux can be installed on an externel device itself and used to boot your computer. Again, externel drives are treated like an internal harddrive. Performance by decline a little since externel drives us UBS for connection and are usually slower then internal connections.
You system's bios must support booting from a USB device. Older systems may give you issues as some, if not most, were designed to use only CD/DVD drives for booting not USBs.
Have a read at this article,