系统情况：win7，在其上使用wubi安装了ubuntu10.04，某天更新时在提示了grub方面的错误，当时没有在意，结果更新重启之后发现无法grub，直接进入了grub rescue命令行之下。
不想重装系统，只是想修复grub。在网上搜索了一下，发现很多人都遇到了这个问题，按照一个老外的方法解决了这个问题：
网址在：
http://ubuntuforums.org/showthread.php?t=1490715
First of all, if you want to keep using ubuntu properly, boot into win7 and remove wubi (after getting your data out). Wubi was never meant to be a long term install, just a quick try.
Right now you have few things to fix, but it would be even easier to fix if you had proper ubuntu, not wubi.
OK...
1. Get a 10.04 ubuntu desktop cd. Use it to load live mode, or Try Ubuntu option. That will load ubuntu running from the cd.
2. Then use these instructions to fix partition #1 on disk /dev/sda:
http://sourceforge.net/apps/mediawik...ms:Boot_Sector3. Open terminal and install generic MBR on /dev/sda with:
sudo apt-get install lilo
sudo lilo -M /dev/sda mbr
Ignore the warnings it will give.
After this restart and you should be able to boot into win7. You have the same error on partition #2 but I think you can get by without fixing it too. Lets see.
If needed, run step 2 for partition #2 also.
Once you can boot into win7 and access wubi, get your data out and think about installing proper ubuntu.
If you have questions about that, just ask.
实际上需要一张ubuntu 10.04的安装盘，也可能还需要一张windows7的安装盘。如果恰巧也解决了您的问题，请在这里留个言，可以让更多人看到解决方法。