Back in the day I could boot from a Windows CD and install/repair over an existing installation in order to correct any problems. Now if I try to do that with a Windows 7 disc on top of an existing Windows 7 installation, it tells me to boot into Windows first and start the process there. How can I do a repair install of Windows 7 if my existing install of Windows 7 is too broken to launch the install from within itself? Among other problems, the Windows 7 DVD setup fails when run from inside my OS with an error 0x80070490 indicating that I don't have sufficient space of ~860MB to run the installation (nonsense: I've quadruple checked and I have over 400GB). For this reason and related reasons I am trying to do a repair install. My main question is the first paragraph of this post, but I will provide additional background to my situation in case anyone has any insight: I have a Windows 7 box running 2x 500GB SATA HDDs in Dynamic RAID 1 (Windows 7 software RAID). I was experiencing lots of Hard Drive strangeness for a month until one Drive finally decided to fail in a detectable fashion. I replaced the drive and reinitialized (resynchronized) the RAID. Since then, the system does not work correctly. Namely, installations or updates of software always fail with various errors (probably the same reason the Windows 7 setup fails). Some programs won't start at all (such as Internet Explorer). I can run Firefox or Chrome and successfully download files, but trying to install anything I download always fails. To be certain I have run what virus or malware scans I already had installed (though some also fail) and found nothing. I've run surface sector scans on both disks several times with no problems found and I have run chkdsk several times with no problems found. My best idea right now is that some critical system files got corrupted when the RAID was failing, and that has carried over to the new plexes. So I'd like to try to do a repair install before I give up and start over from scratch, but I need to be able to do that install without launching my broken OS.

No, repair install Windows 7 by using installation disc must login with administrator first. That a by design behavior. This article describe the detail steps to perform in-place upgrade or repair install for Windows 7: http://support.microsoft.com/kb/2255099 Thank you for your understanding. Regards, Leo Huang TechNet Subscriber Support in forum. If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Did you even read my post? I said I cannot run the setup from within Windows. It fails while unpacking the initial files (I don't even get to select any options) saying I don't have sufficient disk space (this is BS). I don't need to know how to do a in-place upgrade. I already know this and it is failing. I need a way to repair the system from outside the system. I think your reply was an unhelpful way of saying that is impossible. I am confused about why design choices are made that make things worse. If an OS is damaged, why would I want to use the OS to repair itself. It seems much more sensible to perform a repair from outside of the OS. Up until Vista and 7, it seems MS agreed with me. I'm fine with a repair from within Windows as an option, but perhaps someone could shed some light on why it would make sense to make that the only system repair option when the idea of an OS repair by its very nature implies the OS' state is not trustworthy?

Hi, You cannot use installation disc to perform a repair install on Windows 7. Windows 7 is different from Windows XP, it hasn’t the function to use installation disc to repair install. If Windows 7 crash, you can use a system repair disc to restore Windows 7. Thus, you need to create the system image or a system repair disc first, and if Windows 7 crash, you can use this disc to recover. More detail, you can refer this article: http://windows.microsoft.com/en-US/windows7/Create-a-system-repair-disc Thank you for your understanding. Regards, Leo Huang TechNet Subscriber Support in forum. If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, You cannot use installation disc to perform a repair install on Windows 7. Windows 7 is different from Windows XP, it hasn’t the function to use installation disc to repair install. If Windows 7 crash, you can use a system repair disc to restore Windows 7. Thus, you need to create the system image or a system repair disc first, and if Windows 7 crash, you can use this disc to recover. More detail, you can refer this article: http://windows.microsoft.com/en-US/windows7/Create-a-system-repair-disc Thank you for your understanding. Regards, Leo Huang TechNet Subscriber Support in forum. If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. I am marking this as the answer, but I don't like it. It seems stupid and a step backwards (or at least sideways) in OS maintenance capabilities. The option to create a system repair disc is great, but reducing repair options is dumb ... unless someone can provide a technical or operational reason why it makes sense.

Hi, I understand your mind, you can try to submit your suggestion to add repair install option on Windows 7 installation disc: https://connect.microsoft.com/ Regards, Leo Huang TechNet Subscriber Support in forum. If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.