There are a couple of ways to backup and restore your Opera 9 web browser’s settings and files in case you have to uninstall and reinstall Opera or even Windows.

1) Manual Backup: Opera 9.20 has an online help file that shows you what all files and folders you need to backup. Normally one can backup the entire Profile folder and restore it at a later date. But if you want to backup selected settings, files or folders, see below:

Files

Bookmarks: opera6.adr
Notes: notes.adr
Wand passwords: wand.dat (if you had set a master password, you will also need to copy the Certificates files — and set a master password in the new installation)
Contacts: contacts.adr
Cookies: cookies4.dat
Certificates: opcacrt6.dat, opcert6.dat, opssl6.dat
Search preferences: search.ini (if upgrading to Opera 9, you will need to edit this file and change the version number to 8)
Blocked content preferences: urlfilter.ini (new in Opera 9)
Site-specific settings: override.ini (new in Opera 9)
Speed dial: speeddial.ini (new in Opera 9.2)
Widgets: widgets.adr (and the widgets/ folder) (new in Opera 9)

Folders

Favicons: images/
Keyboard (customized keyboard shortcuts): keyboard/
Menu (customized menus): menu/
Mouse (customized mouse gestures): mouse/
Sessions (saved sessions): sessions/
Skins (downloaded / custom skins): skin/
Styles (custom user style sheets): styles/
Toolbar (customized toolbar setup): toolbar/
Voice (customized voice setup): voice/
Widgets: widgets/ (and the widgets.adr file) (new in Opera 9)

2) Opera Backup utility: Opera Backup is a freeware application that allows you to backup and restore Opera settings from one version/installation to another automatically. Download Link

3) Macro to automatically backup and encrypt settings, files and folders with WinRar using Windows keyboard shortcut/hot key. Download Link. More details.