Issue: When Microsoft Outlook 2007 is sequenced and streamed with Windows Vista, the search function in Outlook may not function as designed.
Note: Outlook 2003 does not experience this problem
Cause: This is a known issue with versions of SoftGrid prior to Microsoft App-V 4.5.
Resolution: This problem has been corrected in App-V 4.5. If possible, use Microsoft Application Virtualization 4.5 or later to sequence and stream Outlook 2007 when the target OS is Windows Vista. If Microsoft Application Virtualization 4.5 or later cannot be used then you can modify the following registry key to disable the use of SearchIndexer.exe with Outlook 2007:[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Windows Search\Preferences]
Note: This will enable search to return a result however it will not perform as well as workaround #1.
Source:→ App-V Blog