There is no obvious way to remove a company from “Select Company” list in Sage Account 50.

This is how I resolved this:

• Close Sage Accounts
• Navigate to: C:\ProgramData\Sage\Accounts\2008\COMPANY
• Open file COMPANY with notepad (or other text editor). You will see paths to all companies which appear in “Select Company” list.
• Delete line with the path to company you wish to remove and save the file
• Open Sage Accounts and company in question will be gone from the list

Sage 50 Accounts 2008 Pro
Windows 7 Pro