If you, by downgrading, mean changing to an older version, then no, you can't.
wrong!
You can you must have a backup/copy of the old .minecraft in your roaming appdata folder. just take old one and put in there
In fact... there is an easier process
There is a tool called MCNostalgia which can downgrade your versions of Minecraft. For example, if you don't like some new update (and I kinda do), you can downgrade Minecraft to that version. It currently supports all the way back to Indev (February 2010).
You can download "Minecraft Nostalgia" to downgrade versions of minecraft
You cannot downgrade the browser version of minecraft.
download the Minecraft Version Changer
Google: "minecraft server 1.2.3 download" :D
MCdowngrader
Currently, minecraft is at the version 1.4.5. Look for any tutorial videos online how to downgrade Minecraft.
Use this link. It helped me a lot! After lots of videos this is the only thing that worked for me.
There is a program called Minecraft time machine (or something like that). Download that, and you can downgrade/upgrade Minecraft. You'll need a legal version (you paid for it) of Minecraft for it to work.
There are two ways to downgrade Minecraft:use MultiMC and simply select the version you wantmanually replace the minecraft.jar file in .minecraft\bin with an older version
Go into google and type in minecraft version changer and download it. It's for windows and for mac. Its completely legal and gives you ANY version of minecraft server.
Yes there is. Its a mod that allows you to back your beta.For example, if you have 1.8.1, you will back it to 1.7.1.
It is possible to downgrade your current Minecraft version to a lower version such as Beta 1.7.3 with the use of programs such as the Minecraft Version Changer and MCNostalgia. Be advised that you cannot use mods for the current version, or log onto servers in the current version in an earlier version.