In Windows XP / Vista / 7, it was simple to re-associate items away from the defaults in bulk by using ftype and assoc as below. This was an important time-saver in system setup to make sure that all associations are as the user wants, otherwise it is (very) time-consuming to re-associate each extension one at a time on new installations.
In Windows 8, none of this seems to work now. So for example, .pdf files are now by default associated with Microsoft's Metro app "Reader". To manually have to re-associate the many (10's or hundreds of file types) to standard desktop apps (e.g. .pdf should be associated with Adobe Reader, instead of Microsoft Reader) will be a chore on new Windows 8 installations. Below is an example of how I did this in Windows 7 using a cmd script, but obviously with the advancement of PowerShell it is probably more appropriate for this in Windows 8 (plus, I suspect access to .NET may be required to change these Metro associations, and cmd is a bad tool for that job).
I don't think that Metro apps are bad (on tablets they will be ideal), the problem is that they have massively limited functionality compared to the Desktop equivalents so it would be good to be able to re-associate everything quickly (scripted) to the Desktop apps (or also the reverse if I am working on a tablet and want everything associated to the Metro apps in that use case).
:: File assoc and ftype: RAR, ZIP, NFO, DIZ, CBR, CBZ, DJVU, etc :: #################### :: Note: at commandline, would type ftype txtNFO="%SystemRoot%\system32\NOTEPAD.EXE" "%1" :: but in batch script have to double up the % characters, ftype txtNFO="%SystemRoot%\system32\NOTEPAD.EXE" "%%1" :: plus note the " characters, have to be careful about these if exist "C:\Program Files (x86)\7-Zip\7zFM.exe" ftype 7zFM="C:\Program Files (x86)\7-Zip\7zFM.exe" "%%1" if exist "C:\Program Files\7-Zip\7zFM.exe" ftype 7zFM="C:\Program Files\7-Zip\7zFM.exe" "%%1"ftype txtNFO="%%SystemRoot%%\system32\NOTEPAD.EXE" "%%1" ftype txtDIZ="%%SystemRoot%%\system32\NOTEPAD.EXE" "%%1" ftype QuickPAR="D:\Toolkit\QuickPAR\QuickPAR.exe" "%%1" ftype CDisplay="D:\Toolkit\CDisplay\CDisplay.exe" "%%1" if exist "D:\Toolkit\Microsoft Reader\msreader.exe" ftype MSReader="D:\Toolkit\Microsoft Reader\msreader.exe" "%%1" if exist "D:\Toolkit\Mobipocket Reader\reader.exe" ftype MobiPocket="D:\Toolkit\Mobipocket Reader\reader.exe" "%%1" if exist "D:\Toolkit\Stanza\Stanza.exe" ftype Stanza="D:\Toolkit\Stanza\Stanza.exe" "%%1" assoc .lit=MSReader assoc .mobi=MobiPocket assoc .prc=MobiPocket assoc .azw=MobiPocket assoc .epub=Stanza assoc .par=QuickPAR assoc .par2=QuickPAR assoc .sfv=QuickPAR assoc .md5=QuickPAR assoc .7z=7zFM assoc .rar=7zFM assoc .zip=7zFM