Premiere Elements 11 should work on Windows 10 64 bit.
Please detail the properties of your video files - video compression, audio compression, frame size, frame rate, file extension, interlaced or progressive, pixel aspect ratio.
Often the information about the brand/model/settings of the camera that recorded the video will give the information needed for troubleshooting.
Do you have QuickTime 7.7.6 installed on your computer and are you running the programs as administrator (from user account with administrative privileges)?
Is your video card/graphics card driver version up to date according to the web site of the manufacturer of the card?
Let us start here and then decide what next based on the details in your reply. Any questions or need clarification on the above, please do not hesitate to ask.