Is there any windows software with media player that can protect media data on container level encryption? In other words, users who plugged this HD to a computer with any OS will not be able to copy or view the content unless using this software on Windows OS.
BitLocker encryption is Microsoft's whole-disk encryption tool. http://windows.microsoft.com/en-US/windows7/products/features/bitlocker
There are a number of tools that will encrypt disks and that supply unencryption tools on the disk so that you can access the data when you need to.
The one I'm most familiar with is from Symantec. Not specifically aware of any that are free though.
You can do this with something like TrueCrypt but you need the software installed on every PC (which requires admin access).
I think you could also do it with FreeOTFE. This also requires installing everywhere but does not require admin rights to do so. Here is another, similar tool. And here is a review of some of these tools.
If all your computers are using Windows 7 and contain a TPM module, you could use Bitlocker.
UPDATE: It seems that, whilst I thought that your question could only be answered properly with commercial software such as that from Symantec. You can do this with FreeOTFE. Here is an article explaining the details. The trick seems to be to copy the free FreeOTFE Explorer executable to a non-encrypted USB stick, run it and let it create an encrypted container. You can then run the explorer on any Windows or Mac computer. Looks like performance may be poor though.
UPDATE 2: OK, having looked even further, it seems that there are a few free tools. Here is an article with a couple. I expect you will find others once you see some keywords to look for.