A typical answer from a technical support department. In other words they didn't have a clue what they were doing. Im supprised that they know what Microsoft is!
This is a common problem with outlook express you don't need to do a system restore all you have to do is:
1. Exit Outlook Express.
2. On the desktop, double-click the Recycle Bin icon.
3. Locate the backup file. The file should have a name that resembles mail_folder_name.bak.
Note In this file name, mail_folder_name corresponds to the mail folder that is missing in Outlook Express. If more than one file is corrupted, you may have to restore more than one file. When this occurs, the Recycle Bin contains more than one mail_folder_name.bak file.
4. Right-click each Outlook Express backup file, and then click Restore. The file is restored to the %userprofile%\local settings\application data\identities\user guid\microsoft\outlook express\ folder.
Notes• In this path, %userprofile% is typically C:\Documents and Settings\user_name.
• In this path, user guid resembles {05A26C0D-1173-4013-84A0-EAC2A1FE40F6}.
• If more than one identity profile is used with Outlook Express, there may be more than one user guid. Each unique user guid corresponds to a separate profile.
5. Locate the %userprofile%\local settings\application data\identities\user guid\microsoft\outlook express\ folder.
Note This path contains hidden folders. If you want to view this folder, enable the Show hidden files and folders option in Folder Options.
If the %userprofile%\local settings\application data\identities\user guid\microsoft\outlook express\ folder contains a mail_folder_name.dbx file that is the same as the file that you want to restore, move the existing mail_folder_name.dbx file to a different folder. You can delete this file after you successfully restore your e-mail items.
6. Right-click mail_folder_name.bak, and then click Rename.
7. Change the .bak file name extension to .dbx.
8. Start Outlook Express. Your e-mail items should be restored.
This happens due to
Outlook Express is closed while a .dbx file is being compacted.
• The compaction process is stopped.
• You typically leave Outlook Express running for long periods of time without closing it. For example, you typically start Outlook Express in the morning. Then, you do not exit Outlook Express until you shut down the computer in the evening.
• The .dbx file is very large. For example, the .dbx file is larger than 1 gigabyte (GB).
More info can be found at
http://support.microsoft.com/kb/918069