If you connect to a Pc using Remote Desktop Connection,
the name or the IP Address of the Computer you established a connection
with,are added to the Computer Box.Microsoft states there is no way to
remove this entries as through the registry.To remove the entries
navigate along the path below:


- HKEY_CURRENT_USER\Software\Microsoft
\Terminal Server Client\Default\


Locate here in the right pane the MRU entries.The values of this entries
are the IP Addresses or hostnames you established a connection with.
Delete these entry/entries to clear the Computer Box.



Note:
Every new connection is recorded in the entry MRU0.
The MRU numbers of the older connections are adjusted then,starting from
MRU0,MRU1 and so on.