I've just yesterday installed Windows 10, and I like it. There's only one thing I got a problem with: I've got a folder filled with videos, collected from the internet over the years. These reside on a second HD, the OS is on an SSD.

Now, some (not all) of the videos don't play any more. (they played fine on Windows 8.1) They show no thumb icon in explorer and when clicked don't start to play. Windows Media Player says it cannot play them because I don't have access to the file or because it's already in use, and VLC says the file can't be opened.

Because I suspected this had something to do with file policies, as a test I copied one of the stubborn files onto a USB stick (obviously formatted with FAT32, which doesn't support file policies), and what do you know: from this stick the file plays perfectly. If I want to copy the file back to the original file and choose "overwrite", I get an error, saying the original file can't be accessed.

So this is obviously some file policy issue. How can I fix this? I want all these files to be completely opened up. I'm the only user of this computer, so I don't care about file policies anyway. My user account is an administrator account, so I would think I'd have access to everything. Turns out I do not.

Can anybody help me please? Is there a Windows equivalent of chmod 777?