Office 2010 installed on Windows 2008 R2 with XenApp 6.5.
App-V with Excel 2003 packaged with old Excel 2003 add-in
When the App-V Excel 2003 Application was open – All excel files opened there after or double clicked – would be converted and loaded into the App-V Excel 2003.
When attachments from outlook 2010 were doubleclicked while the APP-V excel 2003 was opened – the attachments failed to open entirely.
Various things were tried
1) deleting the file associations in the App-V package (this was first and foremost as excel 2003 was taking over all associations)
2) trying to force the server to always open multiple instances of excel 2010 with each doubleclick of a file (by editing the HKCR)
For HKEY_CLASSES_ROOTExcel.Sheet.12 and HKEY_CLASSES_ROOTExcel.Sheet.8
This worked on the desktop but changed the core operating behaviour of excel 2010 for EVERYONE – this was not an acceptable solution.
Final Solution: Get the App-V excel 2003 to ignore the double clicking of files by turning off DDE
Tools > Options > General > “Ignore other Applications”