Hi -

You can create a Hotfix / Service Pack requirement for all operating systems that only XP and win2k machines can satisfy.

So find a HotFix, for example, that only applies to those OS's and create the check/rules/role-requirement.

Additionally, you can limit which OS's have access to download the CCA Agent by using the Web Login Page to limit access by OS type.

Let us know if you'd like more info.

peter