Created attachment 57958 [details] screen dump of install dialog after failure. Libre Office installer LibO_3.5.0_Win_x86_install_multi.msi appears to install normally until it gets to the point of "Removing Applications". It then pops up a dialog asking the user to locate the "LibreOffice33.msi". (see attached) There is no LibreOffice33.msi file on the computer so installation fails. There was once an OpenOffice3.3 and there MAY have been a LibreOffice3.3 and they were probably just deleted and not uninstalled (quite common on Windows as deleting the installation files after an install often deletes the .msi) This looks like the same sort of issue as bug 46690 but its version 3.5 instead of 3.4.
Problem is that the LibreOffice installer creates a WINDOWS REGISTRY reference to the original installer program in its TEMPORARY directory. After installation, this installer is ALWAYS deleted to save disc space. THe new version installer sees this entry, can't find the .msi file and hangs. The fix - 1) To install from the CURRENT .MSI file. Run the installer and observe the name of the missing installer (probably LibreOffice33.msi) 2) Run Regedit Search for the offending file Delete the registry item for the .msi file. Continue the search - there may be more than one. 3) try to install Libre Office 3.5 again - Should Work. Of course, editing the Windows Registry is not recommended so the long term fix is 1) Develop a separate installer for the UNINSTALL (like M$ does) Install the uninstall .msi in a safe place (like somewhere in the LibreOffice installation directory so that WHEN (not IF) the installation files are cleaned up, the uninstall.msi will survive. 2) install a registry entry pointing to the uninstall.msi, not the installation msi in its temporary directory. 3) and because of all the corrupted registry's around, just allow the install to proceed without deleting the old version if the uninstall msi can't be found. (previous versions were always happy to install alongside old versions and so should this one because you haven't done anything silly like MS and installed common .dll's in an open directory like Windows or System32 HAVE YOU?
When you say : "There was once an OpenOffice3.3 and there MAY have been a LibreOffice3.3 and they were probably just deleted and not uninstalled" I hope you didn't remove LO/OOo directories only ! :-) If it's what you did, you must clean your registry. You can edit registry as you said but you can also use free tools like Ccleaner or Glary Utilities (I don't claim they're the best ones, just quoted those I use). Then uninstall every LO/OOo you have, remove or backup (if needed) your OOo/LO profiles, use the registry cleaning tools and try to install again. It could be interesting to know if it was LO 3.3.3 or OOo 3.3.3 because we don't know if it's LO or OOo uninstall part which is buggy. About uninstall.msi, I'm not a Windows expert but if it's not already implemented in last LO versions, it sounds a good idea.
Original msi file is not required for the uninstall process. A special msi file is created for that purpose in c:\WINDOWS\Installer\ directory. You need the original msi file only when you want to repair or modify installation. That said, there is no need to "develop a separate installer for the UNINSTALL (like M$ does)" - it just works as designed. It looks like something bad happened to your Windows, and it is not in a clean state. Unless someone else confirms this bug, or you can provide us with a step-by-step reproduction, this bug will be closed.