On a standard machine OMN will install into:
C:\Program Files (x86)\Anquet Technology Ltd
The best place to learn about where your files are kept is by using the Settings->My Account tab within the OMN software. It will list two directories:
Settings and Database files are on a standard machine stored in:
c:\users\<user>\AppData\Roaming\Outdoor Map Navigator
Here you will normally find two files:
settings.xml - your local settings file.
omn.db - a database file which contains definitions of the maps you own and an offline copy of your GPX files along with style information and icons. This database is synced with Anquet Cloud so that this data can be accessed on other devices.
If you delete these two files, you will loose your local settings, and on the next startup you will be asked for your login details. OMN will then re-sync omn.db from Anquet Cloud which will give you access to your personal data.
If you do wish to delete the db file, please make sure you have run sync before hand, otherwise any local changes not synced to Anquet Cloud will be lost.
** If you are running OMN PC Beta, you will also have beta-settings.xml and beta-omn.db
On a clean machine, OMN will save map data to:
C:\ProgramData\Outdoor Map Navigator\pkgs
However, on first run up, if it detects an OMN Classic installation, as OMN can read/share the map data, you may find your map data is stored in:
C:\ProgramData\Outdoor Map Navigator\<userid>\Pkgs
Map data in OMN can be moved to a different drive. Again, the best place to see your exact directories in use is in Settings->My Account within the OMN software.