Is it best practice to install managed client (v12.1.2) on the secondary drive?

I am in the process of rolling out SEP12.1.1. (done 250 out of 1200 clients)

Out of the blue, a Dr. client wants to have it installed it on his secondary drive on a Vista Business OS.

Can you tell me whether this is a Best Practice or anything else that may cause issues?

Yes, I can predict that more will make comments about Vista, especially when Symantec Forum doesn't even list it in the drop-down list for this discussion creation.

thx

willG