WARNING! This procedure requires editing the computer's Registry. Since the computer’s registry is so sensitive to all programs that run on the computer, we recommend that you have your system administrator or IT person follow the procedure.

When you click on the "eTakeoff Application" desktop shortcut and it doesn’t open, it’s most likely due to a value on the ProfUIS registry string that has been corrupted. To resolve, 

• Click on the Start key/Run/regedit.
• Navigate to HKEY_CURRENT_USER\Software\eTakeoff\Dimension56.
• Right click on ProfUIS and select rename
• Rename it to ProfUIS-{#} where "#" is any character of your choosing 
• NOTE: you need to rename it to a unique name that is not is use already
• Close the Registry Editor
• Double-click on eTakeoff Application icon

NOTE: If the above process does not resolve your issue, repeat the process for the "Preferences" registry branch (rename to Preferences-{#} where "#" is any character of your choosing).