When you say booting windows from a second drive, is that another internal hard disk or an external USB one? What version of windows is it? My knowledge is based on versions up to 7, I've not used 8.
It is possible that the power crash just trashed the boot sector of your primary drive so windows can't boot off it. I've had this happen to me before. If so, all the data should still be accessible.
When you boot windows off this second disk, do you have another drive letter in My Computer that refers to your original drive? If so, your original "My Documents" folder should be under the drive letter for that drive, in \Users\\Documents, for Windows Vista and later, and \Documents and Settings\\Documents for XP and earlier. I think XP Home had a single user so it would be
\Documents and Settings\User\Documents
If you can get hold of a Linux Live CD, booting off that won't touch the installed drives. So that is a non-destructive and free way to see if your original drive is accessible in any way.
Last edited by Adam; 31st August 2014 at 10:04 AM.