Hello Manick,
Right click on the .scr file, click on
Properties,
General tab, and on the
Unblock button towards the bottom if there. If not, then the file is already unblocked.
Next, you may be able to just copy the file into the
C:\Windows\System32 folder for you to be able to select to use it in the
Screen Saver Settings window. If the .scr file is not Windows 7 compatible, then this will not work either.
Hope this helps,
Shawn