Question : Partition data became unreadable after NTFS was installed on one of partitions.

I had a dual boot system, with Windows ME on one partition and RedHat Linux 7.2 on another. All was fine until I made a grave mistake: I have replaced ME by XP, reformatting the FAT partition to NTFS.

Not only did this wipe out LILO, but all Linux partitions became unavailable. Both GNU Parted and Disk Druid tell "Unable to align partition properly" and that "The partition data on device hda was unreadable. To create new partitions it must be initialized, causing the loss of all data on this drive".

Any ideas how to rescue my Linux installation?

Answer : Partition data became unreadable after NTFS was installed on one of partitions.

I don't know if this will help, but check out the TestDisk utility at http://www.cgsecurity.org/
Click on the "TestDisk" link on the left side. It's supposed to recover deleted partitions.