Let's say I have a disk which has undergone corruption and I can't boot it anymore.
How can I identify out the file system that has been used for the disk partition in an easy way?
On a Linux system you could use Gpart to scan your disc and guess your partitions.
A live CD version that contains this tool can be found here.
You could download one of the many Linux Rescue ISO images, burn it to a CD, and boot from it. It surely will have this tool or another similar one, better check before downloading.