chkdsk is evil

As title. I erased everything in my drive with chkdsk /r. After frequent trouble with Cygwin, I finally decided to give Ubuntu a try. My drive had 3 logical partitions. I have one with WinXp 64, one with WinXp and the last one without any OS. I tried to install ubuntu in the third partition. I was careless but ubuntu didn’t give much warning. I just went through the guided procedure. After two unsuccessful tries, the boot section seemed to be screwed. I tried bootcfg /rebuild to fix boot.ini but failed and M$ suggested a chkdsk. After chkdsk /r, everything is gone. Amazingly, I only went chkdsk on two of the three partitions. But even the third partition was destroyed. And all three merged into one big partition…