Right, I have tried deleting mail account then uninstalling Outlook (actually all of office)and reinstalling, but still getting same problem.
I have SP3 installed so problem is not related to service packs or hotfixes as far as I can tell (KB301475)
I have checked all previous entries in Techrepublic for same/similar problems and referred to Microsoft KB articles, 290684, 264672, 281064, 281064, 301475, 259416 and 836664.
Most of these refer to altering the registry under HKEY_CURRENT_USER, Software, Microsoft, Protected System Storage Provider and deleting all user subkeys which should look like S-1-5-21-124525095-708259637-1543119021-16701.
I've done all this but there are no subkeys at all, so could problem be related to this?
I've also followed instructions on KB article 836664 which refers to corrupted Pstores.exe and associated .dll files and that hasn't worked either.
From all the google searches I have done this seems to be a very common problem but not necessarily one which is easily rectified.
If anyone has some suggestions other than what has been tried above I would welcome them with open arms!
Regards, Tom