Since Ubuntu 12.04 and 13.10 started recommending 64-bit for most users, you may find that some software doesn’t have a 64-bit counterpart.
If an application you need to use does not have a 64-bit version available, you can trick it into thinking you’re still running 32-bit.
Warnings
Some software may not work this way. Some may cause damage that should be easily reversible (no promises). Unfortunately, we can’t help every individual case, but you can askubuntu.com about specific pieces of software if this doesn’t work.
1. Check for a 64-bit version
First, check to see if the package you want is available in 64-bit. Try googling around, 32-bit will have i386, i586 or i686 in the name, whereas amd64 indicates 64-bit. You might want to include amd64 in your search terms.
2. Trick the app
Start by installing the package ia32-libs. Clicking that link should open the Ubuntu Software Centre, and the install button is located near the top-right-hand corner. If that doesn’t work, then try searching for it in the Software Centre. You might have to click “Show # Technical Items” (bottom left).
Alternatively, you can run the following in the terminal, providing your password when prompted.
sudo apt-get install ia32-libs
3. Install
If you program will still not install (try doing it the normal way), grab a .Deb and try it manually.
sudo dpkg --force-architecture -i Downloads/download.deb