I have Premiere Elements 9.0/9.0.1 on Windows 10 64 bit and have not run into any issues. And, as I have written before, my impression is that Premiere Elements successes and failures are the same before and after upgrade to Windows 10 64 bit.
Consequently, I would start to troubleshoot this issue as a Premiere Elements 9.0/9.0.1 matter and not a Windows 10 vs 7 one.
1. What version of QuickTime 7 do you have installed on your computer along with Premiere Elements 9.0/9.0.1 and are you running the programs from a user account with administrative privileges? Apple has a problem with QuickTime 7 latest version 7.7.8 for Windows 10. Until Apple corrects that problem, please use QuickTime 7.7.6 from the following link QuickTime 7.7.6 for Windows
Even though it is not actually the latest version of QuickTime 7, it will meet the Premiere Elements "latest version" QuickTime install.
2. What are the properties of these film files with which you are having problems getting to the Timeline? What is your project preset?
What exactly is the problem getting them to the Timeline - adding the files to an existing Timeline disturbs that existing Timeline (splits in audio, etc) or something else?
3. Does the problem exist in more than one new project?
4. Are you working with a mouse, touch pad, or pen tablet device?
Let us start here and then decide what next. Any questions or need clarification on above, please do not hesitate to ask.