You can now rest easy, knowing that, indeed, you can install 145 operating systems on one PC.
An operating system needs to reside in a home. That is a partition to me. I used 2x300Gb Pata disk and 2×200 Sata Disk to set up 152 partitions. I always put one operating system in one partition. As an extended partition of each hard disk has no storage of its own, one data-only partition is needed for my personal data, another data-only partition to house the common boot loader and one Swap partition is needed for all the Linux I ended up losing 7 partitions leaving 145 partitions to house the 145 operating systems.
- Link (via Lifehacker)