XenApp 5 is the only version that works on Windows 2008. As far as application compatibility, you can download an evaluation version of Windows 2008 and test the application on Terminal Server. Joe From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Minero, Hector B CIV NSWCDD, K55 Sent: Friday, January 09, 2009 12:44 PM To: thin@xxxxxxxxxxxxx Subject: [THIN] 64-bit Windows 2008 and XenApp Hi all, Is anyone running 64-bit Windows 2008 with PS 4.5 or XenApp or XenApp? I need to upgrade my servers and I'm kind of debating whether to go 64-bit or 32-bit. Mainly using: Microsoft Office, Acrobat, IE, Exceed, Tumbleweed Desktop Validator, ActivClient. I don't want to buy 64-bit servers and find out the these apps. Don't work. Thanks, _______________________________ Hector Minero NSWCDD K55