This a small hack I wrote to bypass the "No previous installation!" error of MicroChip s C18 Upgrade.
Simply run C18Fake and select your C18 installation directory (create if necessary) and click Save button. A "fake" file will now be created into that directory, and this will fool the Upgrade into thinking you already have a former legit installation.
After that you run the C18 Upgrade setup and select the same directory you created/selected before.
Your installation will now begin installing the full C18 package.
