I recently upgraded my laptop's HD. What I like to do is to try out different distro on my laptop. Here's what I am proposing:

1. I create the following partitions:

Windows Partition - Primary, NTFS, Boot
OS Share - Primary, FAT32
Linux root - Primary, ReiserFS
Linux /home - Logical, ResierFS
Linux Swap - Logical

The OS share will be used to share data between Linux and Windows. I used a separate /home because I will be able to maintain the same home directory if I want to install different version of Linux. In addition, I can backup the partition using Acronis TrueImage, which can backup Linux partitions, but not individual Linux directories.

I am assuming that Linux root has to be an primary partition (more on that later).

2. Install GRUB or Lilo on Linux Root Boot sector. Use dd to copy the boot sector to a file and copy it to the OS Share.

3. Copy the boot sector file to the Windows Partition and configure NTLDR to load it. This is why I said I needed the Linux root on an primary partition since I doubt windows allow loading from a logical parition. I am not sure if OS Share would work from a logical partition either.

This should allow me to install a version of Linux on the Linux partition. When I need to switch, I can use Acronis TrueImage to backup the partitions to an image file to be restored later on if I need to.

One thing does puzzled me though. I can get NTLDR to load Grub/Lilo via the copied boot sector file, but will the copied boot sector still work if change the partition size?

Paul

Personally, I just make /boot a separate partition (the third primary on my laptop) and then use grub to dual boot. Then if I nuke the linux / partition or the Windows partition, things will still boot. If I reinstall windows and overwrite the mbr, I just boot a knoppix cd and reinstall grub to the mbr.

In my (limited) experience, the OS share partition and the linux root partition don't care whether they're logical partitions or not.

Just my

If I install a new version of Linux, wouldn't the /boot be toast, too? How do you prevent it from happening other than backing it up?

Don't install a loader with the latter distros, or install it to the root partition.

Works well.
Copying lilo over is a mugs game - has to be done every time you run the lilo command. Grub is better in this respect, but pljvaldez suggestion is best.