This was located for some reason in C:\Users\Public\Public Documents\ACP Config.
You perhaps installed a newer version then moved old files into place? If you had used the Profile feature to move from one system to the newer one, it would have restored things into the right places (or maybe you moved from a very old ACP that didn't even have profiles?). The original change of location of config files was in response to the security changes in Windows 7.