Starting to use Windows 8 CP

IE 10 is installed, and when trying to play a video, I just get a black screen although Flash Player is installed.

Another problem which could be related to the first one, is that when I try to download any file, first it says that the IE could not download the file, and when I click retry, it downloads the file, but changes the "." in the file name to "_", so instead of getting a file "xyz.exe" I get "xyz_exe"

Can you pls help?

Please find attached images of the problem I am facing
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