Yes, you can try this in the meantime, just mount /dev/sda7 which is your Linux root partition. The instructions are independent of the desktop so they will work in either Ubuntu or Kubuntu. Note that after this you may just end up back at square one and you will have to edit /etc/default/grub to get the menu to show again, like you did here. It's worth a try though, sometimes grub doesn't install properly during a full installation and reinstalling grub sometimes fixes problems for people.
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Like the poor fellow that we are helping here, I too bought it to TRY, and didn't want to lose the original OS in case it didn't work out, and I had to return it. However, Kubuntu 12.10 runs on it just fine (or at least as well as this rather unstable release runs on anything). I like the little machine, and I'm glad I bought it -- MS tax and all. However, I had to replace the drive to make it work well. The 245 GB Samsung SSD that I put in it really makes this little machine sing.
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