The installation location for iCu2 8.1 and higher is:

Windows 2000 and XP users:
C:\Documents and Settings\[Username]\Application Data\icu2

Windows Vista and Windows  7 users:
C:\Users\[username]\AppData\Roaming\icu2

Note: These locations are hidden by default. To view the folders, either right click on your iCu2 desktop icon, choose Properties then select find target or open file location

or enable the ability to view hidden folders:

Go to Control Panel - click on Classic View if necessary - go to Folder Options - select the View tab - select Show Hidden Files and Folders - click Apply then OK