Update from unity 3.1 to 3.2

I want to know if I can install unity 3.2 directly without uninstall unity 3.1.

Yes. It is a full install regardless of new version or upgrade. http://unity3d.com/unity/download/

3.2 will automatically uninstall 3.1 for you! upgrade. http://unity3d.com/unity/download/

yes you can! :D just change the installation path

the setup starts after extractions with the status -> removing old unity installation, and then is installing the new version... at least on my win XP machine...

If installing directly means the engine only and that you will overwrite your previous engine version... I would not do that!

As I wrote in the comment in the main post, better you do not install over the previous version, but instead install side by side... rename folders according to versions. Keep everything separate. If you wish to install over previous version create dup installs in, say:(2.6A, 2.6B) and overwrite only one of them... that way your original installs are preserved. Of course do that for the Engine folders and also for the Projects folders. Example: my current project is dead in 3.3, but I am able to continue development in 3.1

Moreover, yes indeed make sure you have proper backups and to test thoroughly your project in the new version before investing time continuing the project.

My particular case may not apply to all projects. Some projects may not be affected a mine is. I have tested thoroughly swapping terrains and objects in completely vanilla test setups to no avail.

3.2 and up versions require new physics setups and some issues must be coded around to eliminate the show-stopper effect they engender.

As of Mar 11th, 2011, versions 3.2… thru 3.3 0f4(63135) render my current project useless.

I have to remain with 3.1 0f3 (54715).

Note: there is a version between 3.1 0f3 and 3.2 that I have missed. Perhaps I can go up to that level... I have to check how I can get it, since now it only offers 3.3... on the auto-update.