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I am trying to install Win 7 SP1 (using Windows Update), but it failed with 0x800F0A12. I have a dual boot configuration windows - linux, otherwise perfectly normal configuration.

This web page: suggest some fixes, but only the first one seems relevant. However I get:

C:\Users\ga>mountvol /E
Access is denied.

The main reason why I am so keen to have it installed is because Windows stopped recognizing my optical drive (it just completely vanished after one of the automatic updates). It might be related to this issue.

An ideas how to fix it?

EDIT: Following @vcsjones' advice I managed to run mountvol /E successfully, but it didn't help with the SP1 installation unfortunately.

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In your command prompt, is it elevated? (It will say "Administrator" in the title bar). If not, run it elevated by typing "cmd" in the start menu search, and holding "ctrl+shift" whild clicking it. Then try your mountvol. – vcsjones Feb 24 '11 at 18:25
@vcsjones: thanks, it did fix the access denied issue. Trying the update again... – Grzenio Feb 25 '11 at 8:17

I solved the problem by going to disk manager and setting the windows C: disk as active. On my setup, that didn't cause any problems with GRUB and everything worked fine.

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Didn't really help :( – Grzenio Feb 25 '11 at 11:26
@Grzenio Can you post what your partitions looks like? There are lots of tips on the various blogs and forums about this, but I'm not sure which are applicable in your case. Do you have the small "windows system" partition? – AndrejaKo Feb 25 '11 at 12:32
what exactly would you like to know? (ideally let me know which cmd line tool to run :) – Grzenio Feb 25 '11 at 15:14
@Grzenio which are your active partitions and on which partitions is /boot and windows C:. – AndrejaKo Feb 25 '11 at 15:38
@Grzenio or better post a screenshot of your partition map – pratnala Nov 20 '12 at 13:31

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