Receiving a file from a different computer is not a big deal however, being blocked from accessing, it despite of having supported application/platform, is. Systems sometimes block file access automatically when belonging to a different computer/source or prompt the user with a warning of whether or not allow access to the file.
The Origination: This is basically not an issue but ntfs alternate data stream security applied by NTFS systems on its files especially on machines configured with Windows XP SP 2 or Vista SP 1 and is also included with Windows 7. Occurrence of this security issue is possible with files received or downloaded via; email, or any other means of transfer that functions on network.
NOTE: Also, this security only comes into notice on an NTFS formatted system partition, i.e. where the source as well as target system have NT File System. In contrary, on a system with FAT file system, the security automatically gets disabled and doesn't interrupt file access.
Situations You May Have Experienced
Following are some circumstances and situations where most users have found themselves caught up with the NTFS security blockage. Let us discuss some of them to get an elaborated and illustrative view at different consequences:
Situation 1: "I am a developer by profession and every time that I download source code to try something new, the respective application blocks me from accessing it. On checking the file property, I discovered that the file security settings show that it has been blocked. There are more than 70 such files that I have and though they can be unblocked right from the Windows File Unblock Properties, but doing so individually with each file is a tiresome procedure. How can I unblock all the files at once?"
Situation 2: "I have developed a few applications that work fine on my Windows Vista machine. However, when I share it with other and they try to download or access it, they are displayed with a security prompt which says that the file has been blocked by Windows as it comes from a different machine. What way can I suggest them to be able to download and run my applications without using Windows File Unblock Properties"
Situation 3: "We recently download a zipped archive consisting of 200+ images using Internet Explorer. However, I was first warned from downloading the archive and now while trying to extract file from it I get prompted with the error that reads somewhat similar to – 'Windows blocked the file (file path) from being extracted'. These files are very important to me. How can I get rid of this issue?"