Olympus Viewer
Olympus Viewer 3 has been retired. It has been replaced by Olympus Workspace
What it is, where to get it
Olympus Viewer is the software that comes free on the CD/DVD disc that is supplied with the camera. Many people now do not have optical disc players on their machines - camera manufacturers need to wake up to this and if they are concerned, just give away a low capacity USB stick with software if they need to satisfy expectations or liabilities. More recent versions of the software will be downloadable from various Olympus websites. - http://ov3-support.olympus-imaging.com/ov3download/ - You need the camera body serial number (on the bottom of your camera)
Manuals
Olympus does not put a lot of effort into providing updated manuals.
There is a 2004 pdf manual - presumably for version 1.2 which is quite old
Probably the most current documentation is in the Help menu when you are running Olympus Viewer.
Video Tutorials
Photocitizen's Processing Raw ORF images
A Youtube video I made for a forum member:
The Olympus Viewer Database
The Olympus Viewer database that stores processing metadata is in C:\Users\myusername\AppData\Local\OLYMPUS
You can specify a non default location in Tools > Options > Advanced
Raw files are seldom modified on hard disk - when you edit a raw file, the edits are save as metadata in a database and/or replicated on companion files, one each, called sidecar files.The program reads the raw file and the metadata from the database or the sidecar and composits the changes to display on the screen or to output to jpeg or tiff. Some newer programs save the edited photo to a new .psd file which contains the metadata as well as the image without making a sidecar file.
Olympus Viewer does not make sidecar files (although it does make thumbnails) - on Windows it stores the metadata for all the edits into one database that is automatically backed up - the hive of folders is here: C:\Users\yourusername\AppData\Local\Olympus
When you move to another Windows machine two things can happen - your Windows login profile identifier may change even though you think you are using the same login name. For example, on one machine, my id is anand and on another I am ananda and on another I am ananda1 - so I think I am me but the physical location of the c:\users\yourusername is different. When you take the nest of folders and files from an external usb stick or hard disk and try to make a new home for yourself on a new Windows machine, you have to nominate where these things are kept.
In Windows the external drive letter may change. On one machine, your external drive may be D: and on another machine it may be E: The Olympus Viewer database may expect the raw files are on D: When you move to a new machine, place the database in the c:\users\yourusername but your raw files on the new machine are on E: then no go. You have to use Windows Drive Letter Mapping to ensure that the external drive letter on the new machine matches the original drive letter.