During installation of PureMessage for Microsoft Exchange, the following error message is displayed:
Setup was unable to start IIS.
Error details: COM error-code 0x80004005: Unspecified error.
The installation continues after this error message.
First seen in
PureMessage for Microsoft Exchange
An IIS related file iisrstas.exe is not registered correctly on the server.
What To Do
Follow instructions from this Microsoft kba