Possible reasons for this error are explained in the following articles:

MS KB 296512 - "OLEXP: Error Message: Outlook Express Could Not Be Started
Because Msoe.dll Could Not Be Loaded"
(http://support.microsoft.com/?kbid=296512) where the problem is due to
problems with the Address Book.
MS KB 272265 - "OLEXP: Error Message "Outlook Express Could Not Be Started
Because MSOE.DLL Could Not Be Loaded" When You Start Outlook Express"
(http://support.microsoft.com/?kbid=272265) where the problem is caused by
mixed file versions
MS KB 232480 - "OLEXP: Error Message: Outlook Express Could Not Be Started
Because MSOE.DLL Could Not Be Loaded"
(http://support.microsoft.com/?kbid=232480) where the problem, similar to
the one above, is due to uninstalling a later version of IE/OE.

The slightly different error messages "Outlook Express could not be
started because Msoe.dll could not be initialized" and "Outlook Express
could not be started. The application was unable to start the Internet
Account Manager." when attempting to start Outlook Express are often due
to missing or corrupted information in the Outlook Express Identities
registry key.  For more details see KB 245419 - "OLEXP: You Receive an
Error Message or Are Unable to Start Outlook Express"
(http://support.microsoft.com/?kbid=245419). Check this KB as it explains
how to remedy this error.

From  http://www.fjsmjs.com/OE/directdb.htm

Errors in DIRECTDB.DLL or MSOE.DLL generally indicate corruption in the
message store.
Start by moving Folders.dbx to an empty Windows folder (with OE closed).
Note:  the DBX files are hidden in Win2K, WinXP and Win2K3.  You will lose
your folder hierarchy and the lists of newsgroups on the news servers, but
it might get you into OE.

If that doesn't do it then move all of the DBX files to the same folder as
Folders.dbx (again with OE closed).  You should now get into OE.  Try
importing the messages from
the folder you moved the DBX files to.  If you can't, you can use this tool
to extract the messages:

DBXtract ($5):
http://www.oehelp.com/DBXtract/

Note:  It can take a long time (days with really large folders).

The messages can then be dragged from the Windows folder back into a folder
in an open instance of OE.