I want to install it with 4.2. but I can’t find the option to do so.
How do I put it back?
Many thanks.
Windows 7
AMD 64
See: LibreOffice 4.2 Changes · Installer (win only)
The option to select which Modules to install has been removed from the Windows Custom install dialog (Andras Timar). The option made little sense (all the modules are included in the program: it was just the Start Menu icons/shortcuts that were suppressed) and was a source of bugs.
UPDATE (2014-02-04)
Reported as Bug 74467 - Unable to install missing modules after upgrade to 4.2
Status: RESOLVED WONTFIX
“Workaround exists. You can remove 4.1 and the install 4.2, feature state is only preserved when you do an update.”
See also the comments below:
I saw that announcement in the release notes. I installed 4.2 over 4.1 and the new install kept the exiting configuration, i.e., no Impress. There is no option I can see to call up Impress – it doesn’t seem to exist on any menu – and LO won’t read an Impress/PP file.
You may run the installer again, and select Repair.
Repair unfortunately doesn’t help. I have no Base and Math and suddenly I needed the latter. Looks like module selection screen was not only about shortcuts after all. 
Best workaround (that I know at the moment) would be: uninstall v4.2.0, then install v4.1.x (custom setup) with all modules, then install v4.2.0.
Feel free to file a bug report.
For users with installed v4.1.x (customized modules): Before upgrading to v4.2.0, first run the 4.1.x installer again, and select Modify, then select all modules.
Thanks. Unfortunately downgrade is not an option for me (heavy customization, I don’t wan to lose my settings). I filled a bug report.
Bug 74467 - Unable to install missing modules after upgrade to 4.2
Status: UNCONFIRMED RESOLVED WONTFIX
@Seji – “The user profile is the folder where the all user related data (extensions, custom dictionaries, templates, etc) is kept. This folder is not eliminated when LibreOffice is uninstalled or updated, preserving the customization performed by the user.”
@manj_k - This is assuming you uninstall the normal way, not with some special uninstaller like Revo.
For UbuntuStudio 16.4, Impress can be installed by choosing to install Impress in ‘System’>‘Software’.
It got seemlessly integrated with the LO package.