Best way to reinstall wow?

I reformat/replace HDs about once a month for work reasons. Prior to cata I had a WOTLK that would install wow/bc/wotlk and from there I had all the patches backed up to install and save time.

Now there are alot of options to install, which would be the best and fastest? without downloading too much content.

WoW 4.0 download direct download+Cata download, Cata DVD, Wotlk installer+Cata dvd, 4.0 Download+Cata dvd?

 

i simply keep wow on an external HDD, easiest for me

if you don't have to worry about bandwidth, you can do any of the above

 

Definitely use the CD's if you have em. The Cata disk will install everything then you just need the patches.

 

Guess I'm going to do a clean install via download only. Once thats fully patched I will copy it over to my spare drive and keep it as a backup for future installs.

 

update it for every major patch as well

 

Just to be sure, I can use the install as a backup right? I don't NEED to reinstall everytime