PostgreSQL data directory/files portability
The best option is probably to install PostgreSQL 9.1 from http://apt.postgresql.org/ if it's available for your distro/version.

If not, you can install a temporary copy of your old Ubuntu version in a VM for recovery purposes - use virtualbox, kvm, etc. Vagrant can make life easier, just grab a prebuilt Ubuntu box from https://vagrantcloud.com/search?utf8=%E2%9C%93&amp;sort=&amp;provider=&amp;q=ubuntu , bring it up, restore your DB, dump it, and shut the box down again.

A PostgreSQL data directory from Linux is not compatible with PostgreSQL on Windows. So you cannot use a 9.1 install on Windows to restore your data from Linux.

Once you've recovered, set up regular backups.