I do have some free time now, so I will be reviewing through the testnet thread and getting things launched off of my tablet-top (I previously used it to mine BBP so I know it works.)
The windows download link is in the OP post; it would be good to run testnet from a machine that has crashed for you before; then you can mine against prod with that machine using the testnet binary.
But yes, you can start with any machine you want to get acclimated to testnet also.