Hi John,

World of Computers in Cambridge are a good source for windows 7. I purchase all my licences and media for boot camp use here and have never had an issue. In your opening post you say that you are looking to control the HD621 with RS232. Do you mean configure?

Cheers
Tom

Main: G61SL, 218, HD621, 2*7200SE, 7200HCSE, M6s, DSW, Apple TV 4K, NUC (Roon server)
Secondary: Wiim Pro, 3200, Audio Core 200
F80