Windows 2000 support for everyone who asked:
If you have already installed KMDF v1.0 on your machine, you will be asked to
remove the v1.0 bits before the v1.1 bits will install. This is by design.
You cannot have KMDF 1.0 and v1.1 side by side next to each other when your driver is deployed. V1.1 is a superset of v1.0. When KMDF is deployed, only the latest minor version is loaded so you cannot have v1.1 and v1.0 on the same system. As such, it does not make much sense to have v1.0 and v1.1 on the same dev system. Once you are compiling against v1.1, v1.0 doesn't come into play.
You will initially see the v1.0 installer because you need to remove v1.0 before the v1.1 installer will run. There is a bug in the v1.0 installer we shipped which is why we can't do the uninstall from the v1.1 installer. Once the v1.0 installer has removed the v1.0 bits, you have to manually restart the v1.1 install from the Install KMDF link on the CD.
For those who want to create a completely unsupported DDK environment, you can make the 2 installs to live side by side. First make copy of KMDF10 into a new sibling directory (KMDF10.orig for instance). Then let the v1.0 uninstaller run and remove the v1.0 bits. The directory you just created will still be present and contain the v1.0 bits. Now run the v1.1 installer again and you have both on the disk at the same time.