The location you are most interested in is "
C:\Users\*yourusername*\AppData\Local\Microsoft\Outlook
The file you are most interested in is the PST file. It should contain emails and your Contacts.
Save all PST files, that you can find.
Once you reinstall Outlook 2010.....
File / Open / Outlook Data File
Find the location of the saved PST files and open them. They will open as an archive (personal folder) below your main mailbox. At the very bottom you will see some icons. If you mouse over them you will see Folder List, click it. Now look through those folders for your contacts.
OBI files - are RSS Feeds, which you may or may not have setup or be interested in, but they do not contain email or contacts.
INI Files - Not needed.
The folders, one is probably RoamCache and is probably not important. Not sure about any others.