Installing Windows 7 Without A CD Drive

Is it possible to install windows 7 to a HTPC without a cd drive. I am thinking along the lines of installing on seperate computer then swap out the hdd, would this work?

Sure extract the ISO from DVD using ImgBurn or download the latest for your licensed version from Windows 7 official ISO downloads.

Then write to 4gb+ flash stick using UltraISO Software To Create Bootable USB Flash Drive which always works for me. You can even keep the stick bootable while storing other tools or files on it. Just leave the 7 install folders in the root when you want to boot it to install.

I havnt got an eight gigabyte flash drive BUT i have got a large partitioned external hdd. Would this still work

4 gb will work. Not sure about external since I've not tried it or seen much about it but you can google how-to if UltraISO won't write it like a stick.

You may use this guide:
Install Windows 7 From USB

This explain how to do it yourself instead of relying on external tools. It probably works too on a full external HD as well as a normal pendrive, but you must mae sure that your BIOS support booting from it.