How do I eradicate a worm identified as MSVXD.Exe which appears at the
start-up of computer

Hello, june1974:
  The worm you are infected seems to be W32/Datom-A, follow this link
to know more about it:
  
W32/Datom-A  
http://www.sophos.com/virusinfo/analyses/w32datoma.html  

There you can read the process to disinfect your system:

Disconnecting from the network
Before disinfection, disconnect all infected computers from the
network to stop the worm spreading. Follow the above instructions for
removing worms, remembering to scan computers again after disinfection
to make sure they're clean.
At the taskbar, select Start|Run. Type 'Sysedit' and press Return.
Bring Win.ini to the front. Search for the text "msvxd.exe" and delete
it if it exists. Save the file.

Windows NT/2000
In Windows NT/2000 you will also need to delete the following registry
key. The removal of this key is optional in Windows 95/98/Me.
At the taskbar, select Start|Run. Type 'Regedit' and press Return. The
registry editor will open.
Before you edit the registry, you should make a backup. In the
Registry menu, click 'Export Registry File'. In the 'Export range'
panel, select 'All', then save your registry as Backup.
Locate the HKEY_LOCAL_MACHINE key:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run\MSVXD
and delete it if it exists. Close the registry editor.

After disinfection
Reboot your computer.
When you are sure the network is clean, you can reconnect to the
network the computers you have disinfected.

Also, you can use this tool to remove that virus:

AntiDatom Removal Tool 1.0
http://www.webattack.com/get/datomremoval.shtml

I hope this is the information you were looking for and don't hesitate
to request for any clarification.

Search strategy

MSVXD.Exe
://www.google.com/search?q=MSVXD.Exe&sourceid=mozilla-search&start=0&start=0

Regards.

Your advice seems to have solved the problem 
Many mant thanks
june1974