Windows Live OneCare has come under fire for deleting users' Outlook or Outlook Express email files.

The problems arise when OneCare detects an email with a potentially dangerous attachment and responds by quarantining or deleting the .pst folder that holds all the users' Outlook emails.

One user, AN525-24, who was the first to spot the problem and report it on Microsoft's OneCare forum, has been reporting endless problems trying to recover the deleted emails. He argues that Microsoft owes him for its mistake.

"I have recommended Windows Live OneCare and installed it on about 30 systems. I am sure that when those systems go to hell I will hear about it...Does Windows owe us anything for their problem? I know when I make mistakes at my business it costs me," he wrote.

Other users berated the OneCare support staff, complaining of poor support, false accusations and staff not following up on promised deadlines, both for calls and for a patch to fix the problem.

Microsoft forum administrator Stephen Boots was very surprised by the appearance of the bug as apparently it was an issue that been dealt with over a year ago, but somehow resurfaced recently in version 1.5 of the OneCare program.

According to another user on the forum, 'bestm80eva', after installing OneCare onto a customer's PC "she rang me in tears the other day [saying that] 3 1/2 years worth of email have gone missing".

"Now I ask you if MS can't get the outlook team to talk to the OneCare team what hope do we have as users of there OS and reading here the temporary solution is to exclude the outlook folders," he said in his post.

"Well surely the temp solution would be to hot fix the software so it did this automatically. 80 per cent of the users out there would not know a 'pst' file if it bit them."

Microsoft has acknowledged the bug, and has posted a series of steps to recover the file from OneCare's quarantine. However many users have reported that the file has been deleted completely, effectively destroying all their emails and contacts.

To recover lost email users should try the following steps:

To ensure that the problem does not continue until the next update, Microsoft said users should also do the following:

According to Microsoft the latest patch fixes the bug, but many people on the forum are still having problems recovering and repairing the deleted information.