If you try to update an existing LibreOffice ( In the test most 3.4.4) the installation stops after warning, that all components of 3.4.x should be closed (In fact, they are...)
On the German-ML tested with:
LibreOffice 3,4,4 --> 3,5rc1 (windows 7 hp x64) HANG
LibreOffice 3,4,4 --> 3,5rc1 (windows XP x86) OK
LibreOffice 3,4,x --> 3,5rc1 (windows 7 pro x?) HANG
LibreOffice 3,4,x --> 3,5rc1 (windows Vista hp x86) HANG
ML Thread: http://listarchives.libreoffice.org/de/discuss/msg10673.html
This looks like bug 36677 (and its many dupes). See in particular comment 3 of bug 43454:
> It is impossible to fix this, because LibreOffice 3.4.4 is released and the bug is in LibreOffice 3.4.4 installer. It was fixed for 3.4.5, see bug 36677.
> Workaround: First you need to uninstall 3.4.4. It usually works in interactive mode, or you can use uninstaller tools such as Perfect Uninstaller.
I suppose we now have another work-around: upgrade to LibreOffice 3.4.5 and *then* upgrade to LibreOffice 3.5.
It remains very annoying that we cannot "fix" this in the *new* installer.
*** This bug has been marked as a duplicate of bug 36677 ***
I have mentioned it at http://wiki.documentfoundation.org/ReleaseNotes/3.5#Most_annoying_bugs