I was wondering... Would it be possible to download Minecraft from the website a second time, keeping the one I already use, then have the new one updated to 1.1 and the old one on 1.0 so I can still use Minetown? I'm not willing to try it so if someone else already has tried it or knows the answer please let me know <object class="emojione" data="https://resources.enjin.com/1489581540/themes/core/images/emojione/svg/1f642.svg?0" type="image/svg+xml" standby=":)">:)</object>

Yeah. If you just rename the .minecraft folder to something like MC Backup, then that will save, and you can just launch the client, and a 1.1 folder will be made. To go back to 1.0, just rename it back to .minecraft, and name the new .minecraft folder to Backup

If you have updated, you can't. You must downgrade first. If you're using Windows 7. Check my post in Amaryxi's thread "Have You Updated? - The Fix"