Yes, everything which is cached and stored in there will be gone...
Also:
quote:
Originally posted by Mess.be
Using the "Cleaner" option in the Sharing Assistant will result in loss of data, such as shared content, cached contacts, etc. It is strongly recommended that you perform clean up after backing up your data, and if -and only if- instructed to do so by Support.
WLM is a beta, so you shouldn't be using it anyways for your everyday/normal chatting, but for testing...
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BTW: I suppose you also tried to simply delete the file in Windows Explorer (while Messenger isn't running)?
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