Wjview lets you view window-based Java applications.
A possible cause of the error message is if Wjview attempts to start an
application on your system that no longer exists. To check this, perform the
following steps:
1. Start Msconfig.
2. Select the Startup tab.
3. Scan the list for any entries that contain "wjview."
4. If you find any "wjview" entries, try disabling the Wjview startup
component and locate any associated folders identified in Msconfig that you
might need to delete to determine whether that solves the problem.
To delete the "wjview" entries rather than disabling them, perform the
following steps:
1. Open a registy editor (e.g., regedit.exe).
2. Navigate to the
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
and
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run registry
subkeys.
3. Remove the invalid "wjview" entries.

Note you can save the registry key first by:
On the File menu, click Export.
In the File name box, type SaveKey, and then click  Save.
Or create a system restore point prior to editing.
Note: If the registry key is not there, you can simply create one by going
edit > new.

http://support.microsoft.com/default.aspx?scid=kb;EN-US;322756
HOW TO: Back Up, Edit, and Restore the Registry in Windows XP
Disclaimer: Modifying the registry can cause serious problems that may
require you to reinstall your operating system. Use the information provided
at your own risk.

"WJView Error at Startup":
http://www.mvps.org/sramesh2k/WJViewError.htm

I get an error message when I start up my computer:

WJView Error: Could not execute main.  The system could
not find the file specified.

Anyone know what this means/how to resolve it?

Thanks,
Hilary