Cannot save modified hdparm.conf

[csodabogar]

Hello!
Yesterday I have installed Knoopix for the first time. I didn't pay attention, I guess, and it created a Reiser partition for the system.
While booting Knoppix displays something like DMA is not enabled and could slow fsck progress. Done some googleing and found out that I have to modify /etc/hdparm.conf. Found the file, modified it baut it gave me a write error. Since the installed Knoppix cannot see the Reiser partition, I booted my computer with the live cd. Modified read/write state but still got some write access denied error.
Any idea how to fix that?
It's annoying that live cd begins autoconfiguring devices much faster than hd install.

[maxIT]

Are you sure to be 'root' when try to write the file? Conf files in /etc require root privileges to be edited (with rare excepions).
If the reiserfs format was the problem you not only would be in trouble to write the file, but even to read it.