Okay so here is the problem...


Every time I restart my computer I get a popup of "Choose the program you want to use to open this file: Registration Myst V"


Even AFTER un-installing I still get this problem.. and the Ubisoft folder is completely gone. I have no clue where this is coming from and it's really annoying.

Assuming you're running Win XP, try the following:
-- a. Click on Start > Run.
-- b. Type Msinfo32.exe in the Open: box.
-- c. Click on OK to run the System Information Tool.
-- d. On the top taskbar, click on Tools, then on System Configuration Utility in the drop-down menu.
-- e. Click on the Startup tab.
-- e. Scroll down to the "Registration Myst V" entry, and uncheck the box.
-- f. Click on Apply, then on OK.
-- g. Reboot.

Re-install EoA as detailed in Myst V: Clean Boot Install/Re-install With Win XP, one of the stickied topics at the top of this Forum.