View Full Version : [ubuntu] error prefix not set

May 13th, 2011, 12:34 PM
I installed from wubi when I restarted and went to boot up ubuntu I got the error prefix not set.

wn7 64

please help

May 14th, 2011, 10:00 AM
Did you search WUBI megathread? See this post: http://ubuntuforums.org/showthread.php?p=10771873#post10771873

According to the above post by bcbc (expert in WUBI),

In terms of warnings/messages, there's the one grub boot message about the "prefix not being set". This is new in Natty, but it is a known issue and harmless.

So what happens after getting this message? Posting the exact error messages would be helpful.

May 14th, 2011, 02:49 PM
it throws me to grub command prompt

May 19th, 2011, 05:51 AM
Well, for best advice, bcbc is your man! Follow these links and his suggestions to see if any works for you:

May 28th, 2011, 02:25 PM
hi cure2001 have you sorted this error...!!! I started receiving 2 days ago :P

May 28th, 2011, 02:42 PM
hi cure2001 have you sorted this error...!!! I started receiving 2 days ago :P
Did you check the possible solutions in the links provided by varunendra?

May 28th, 2011, 02:48 PM
I saw them... but i didnt tried them yet... I dont know if they will work... or trying them should not lend me with some other issues.. :P

May 28th, 2011, 06:34 PM
This error message was reported to the developer and he stated that it wasn't causing any problems and he wasn't going to try to fix it (in case something broke in the attempt). See comment 28 and 29 here (https://bugs.launchpad.net/wubi/+bug/693671/).

My natty wubi install(s) have all reported this "error" on every startup.

So... I think there is likely some other problem and you're assuming it has something to do with this error message.

My steps to trouble shoot would be:
If you don't see the grub menu
1. confirm that the file \ubuntu\disks\root.disk exists or find it (search by name and/or size since windows chkdsk will sometimes rename files it considers corrupted)
2. back it up once you find it
3. run chkdsk on windows.
4. if you still can't boot, boot a current Ubuntu CD ("Try it" without installing) and fsck the root.disk (https://wiki.ubuntu.com/WubiGuide#How can I access my Wubi install and repair my install if it won't boot?).

If you see the grub menu but booting fails
1. Try the recovery mode and try to repair if that works
2. Try an older kernel if you have one available
3. Boot a current Ubuntu CD and run the bootinfoscript (http://bootinfoscript.sourceforge.net/) results, then post them on a new thread asking for help if you can't get it working.

September 22nd, 2011, 07:23 PM
For what is worth, I was having the same issues after having Ubuntu 11.0.4 up and running for over a month. After looking at the files system under Windows I noticed that my root.disk file had 0 bytes. Something, either Windows 7 or Ubuntu itself, corrupted the file. Luckily I had a backup of my computer including my ubuntu install so I was able to recover by replacing the bad root.disk file with a previous version. Hopefully this information would throw some light into this problem.

December 25th, 2011, 02:17 AM
OK I had this same error. I do not know what but their is something wrong with the new wubbi the orange one. I had to install Ubuntu 11.04 from the old wubbi and then get the upgrade. The reason my computer crashed and burned earlier is because I was working with the split command trying to learn more about the terminal and large text files. Then it crashed i rebooted and then got the message prefix not set. Frustrating.

February 5th, 2012, 11:32 PM
sorry guys but i surly reach this blief that u are so weak at answering this problem...
i like linux but when i can not soleve my prob so i cant use it..
pls tell us a clear answer

October 5th, 2012, 05:01 PM
I am not using Wubi and I've got the same error. I do have software raid thou.