What makes you think that? I know that the explorer is tightly integrated inot the OS, but it can be re-installed (as the guy says he has re-installed it!)
click here You'll find the top download in microsofts internet download area is in fact Internet explorer 6 (with SP1)...
And if you go to windows update without IE6 you will be prompted to install IE6...
There thats two ways how you can install and re-install IE6 without having to Fdisk format and start again...
And on the subject...
All Fdisk does is set the partition table, it is not necessary to run Fdisk each and every time you format a machine, only if you want to chage partition sizes!