How to remove RDP history
To remove entries from the Remote Desktop Connection Computerbox in the Windows Remote Desktop Connection client, start Registry Editor, and then click the following registry key:
Entries appear as MRUnumber, and are visible in the right pane. To delete an entry, right-click it, and then click Delete.
Removing Entries in the Mac Remote Desktop Connection Client
To remove entries from the Remote Desktop Connection Computerbox in the Mac Remote Desktop Connection client, delete the Users:Username:Library:Preferences:Microsoft:RDC Client:Recent Servers file.
Notes
The list of all destination connections (including previous connections) are stored in an MRUnumbervalue in the following registry key:
Every new connection is given the value of MRU0, and the other values are then sequentially moved down in number. The MRU value can contain a Fully Qualified Domain Name or an IP address of the computer to which you connect. For example:
MRU1 REG_SZ computer.domain.com