I personally preffer the classic installer, as it's ~2mb smaller, installs faster and as i'm not really a big fan of msi installers in general(they're bloated and leaves a copy of the installer in '%windir%\Installer' etc...)
Anyway, the classical installer is hidden on the Opera homepages download section, but can be found by selecting 'Show other versions > Windows' and then selecting the latest version on the top of the list...
The classic installer is a Wise installer which accepts the '/s' command-line argument for silent installs and it will by default make the desktop, quicklaunch and start menu shortcuts, but you'll still need to add the reg-entries for making it the default browser on your system...
These are the exact ones Opera sets:
CODE
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.htm]
@="Opera.HTML"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.html]
@="Opera.HTML"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.mht]
@="Opera.HTML"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.mhtml]
@="Opera.HTML"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.xht]
@="Opera.HTML"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.xhtm]
@="Opera.HTML"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.xhtml]
@="Opera.HTML"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\http]
"EditFlags"=hex:02,00,00,00
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\http\shell\open\command]
@="\"C:\\Program Files\\Opera\\opera.exe\""
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\http\shell\open\ddeexec]
@="\"%1\""
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\http\shell\open\ddeexec\Application]
@="Opera"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\https]
"EditFlags"=hex:02,00,00,00
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\https\shell\open\command]
@="\"C:\\Program Files\\Opera\\opera.exe\""
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\https\shell\open\ddeexec]
@="\"%1\""
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\https\shell\open\ddeexec\Application]
@="Opera"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Opera.HTML]
@="HTML Document"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Opera.HTML\DefaultIcon]
@="C:\\Program Files\\Opera\\opera.exe,1"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Opera.HTML\shell\open\command]
@="\"C:\\Program Files\\Opera\\opera.exe\" \"%1\""
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Opera.Image]
@="Image"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Opera.Image\shell\open\command]
@="\"C:\\Program Files\\Opera\\opera.exe\" \"%1\""
[HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet]
@="Opera.exe"