I have upgraded numerous farms from 4.0 to 4.5 as in-place upgrades and never had an issue. Not much changes from 4.0 to 4.5. XenApp 5 for Server 2003 is the same thing as 4.5 FP1. Webster From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Angela Smith Subject: [THIN] Citrix Presentation Server 4 upgrade to 4.5 query Hi Im looking at upgrading my Windows 2003 / Citrix Presentation Server 4 farm to XenApp 4.5. I cannot migrate to new hardware. There are 2 options: 1) Uninstall Citrix Presentation Server 4 and Install XenApp 4.5 2) Install XenApp 4.5 over the top of Citrix Presentation Server 4 Im looking at Option 1 as I feel it may be cleaner. Can anyone recommend the best way to upgrade and ensure no issues are encountered.. Which option should I go with? Thanks Ang