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Use the x64 MSI if you don’t have Office installed. If you have Office installed, use the bit version that matches the Office version (e.g. Office 32 bit needs PowerDesktop 32 bit). Visit: https://pdocs.atlassian.net/wiki/spaces/PD/pages/55345410/Requirements+and+Setup#Enterprise-Deployment
And of course, for any first-time install, use the EXE.
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Please see the current requirements here: https://pdocs.atlassian.net/wiki/spaces/PD/pages/55345410/Requirements+and+Setup#Requirements
To find the bitness in Office
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For any machine that hosts PowerDesktop with the PST Import, Outlook must be installed! See Requirements
The PST module requires MAPI. You used to be able to install a MAPI component, but that is no longer available via Microsoft, so the alternative is to install Outlook on the machine. End users working on their own workstations are very likely to have Outlook already installed, but where the application is installed on a server, Outlook is (generally) not installed by default. Litera is looking into switching libraries in the future to avoid this requirement.
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