The software is excellent with footages originating from cameras. That I can vouch for and that I think is the best way to use the software, when you want to edit videos shot/captured from video cameras. You usage, even if it is only for test, involves a wmv file. First, wmv is not a great format for editing, in fact it is a pathetic format for editing. You should try other file formats. Take a footage from a camera and then test it out. There are veterans in this forum who will swear by its performance with these footages. I understand your usage of wmv coming from Windows Movie Maker world, but trust me, that is not an ideal way to judge a video editing software.
Second, There is something called a project setting that needs to be understood before trying to play back video files within PrE10. If the clip matches one of the multiple project settings that the software holds, it will switch to it and the playback should be very smooth. And these project settings are very close to what the video cameras dish out with their resolutions, formats and frame rates
If you get these two right, and if you have the right display drivers, you are most certainly not going to see any issues with playing back files. Let us know if any of this does not make sense or does not work!
Welcome to the forum.
The MOV is but a wrapper, and much can be inside that. See this ARTICLE for more info, and also tips on how to "peek" inside the wrapper. Please let us know what CODEC is used in that MOV file.
Also, playback can depend on several aspects of one's computer. With most AV material, the important aspect is the I/O sub-system, i.e. the HDD's, their speed, size, free-space, controller type, and how they are allocated to the Project. Then, with some other material, especially many flavors of the H.264 CODEC, it is dependent on the speed and number of cores of the CPU.
Can you tell us the specs. of your computer? This ARTICLE goes into detail on what info is needed.
As VDOSurfer points out, choosing the correct Preset (at New Project) to match one's Source Footage 100% is very important. The article, linked above, will tell you how to let us know what Project Preset you chose, and the first question will help define what that Project Preset should be.
Read Bill Hunt on a file type as WRAPPER http://forums.adobe.com/thread/440037
What is a CODEC... a Primer http://forums.adobe.com/thread/546811
What CODEC is INSIDE that file? http://forums.adobe.com/thread/440037
Report back with the codec details of your file, use the programs below... a screen shot works well to SHOW people what you are doing
If you have a red line over the timeline after importing a video and before adding any effects... your project is wrong for your video... read above about codecs
Once you know exactly what it is you are editing, report back with that information... and your project setting, and if there is a red line above the video in the timeline, which indicates a mismatch between video and project
More information needed for someone to help... click these links and provided the requested information
Now, specific to PreElements
Right click the PDF link in the upper right corner and select to save to your hard drive
Steve's Basic Training Tutorials http://forums.adobe.com/thread/537685