Hi, We have demo'd 3CX for some time with no problems; even playing with the configuration (had a look at ACT! CRM integration and Outlook / SKYPE) . All worked fine under XP Pro, but on upgrading to WIN 7 Pro 64Bit we seem to be hitting brick wall after brick wall. (We are using IIS not other (Abyss?)) My main problem is our Yealink T20Ps are not being picked up by 3CX and therefore cannot be provisioned. They where okay under XP Pro. (I tried with win phone v6 under Win 7 64bit and all okay) Firmware 22.214.171.124. Also tried on the 9.60.x.x firmware. I have read a lot of posts but not found the answer to this. Could anyone nudge me in the right direction?