Looking at the MS forums, there seems to be several things that can cause this issue, so it's hard to know for sure what's going on, but I think the problem here was caused by the way you installed Ubuntu. If you shrink the Windows partition with disk manager first, you don't want to choose install alongside windows. I believe that shrinks the Windows partition again, leaving the other space unused. I suspect either the Windows partition is now too small (Windows 7 seems to need 40 GB) or file corruption is causing Windows to see the disk as damaged.
You might try booting from a live cd/usb and use gparted to delete everything but the Windows partition. Boot into Windows (you will probably need to restore the Windows mbr with a restore disk. Google that if you don't know how, it's easy.), then run chkdsk. When reinstalling Ubuntu, choose the option to use the available space (easy) or use the partitioner to create the partitioning scheme you want in the empty space first (much more advanced if you haven't done it before).
If disk manager still does not open after running chkdsk, use the live distro to expand the size of the Windows partition, probably to fill the entire disk. When reinstalling Ubuntu after this you can use the Install Alongside option.