So many factors can affect your performance.
What operating system are you using?
How fast is your processor, how much RAM do you have and how much free, clean, defragmented space is on your C or main drive?
What model of camcorder is your video coming from and what format and resolution is it?
When you started your Premiere Elements project, which project settings did you select? If you've selected the correct project settings for your video, you will see NO red lines above your clips when you add them to your timeline. Is that the case in your project?
Many thanks for that. I have windows 7 running on a core 2 Duo processor with 4Gb or RAM and 23GB of gree space on drive C. The dark red video plays this way in Windows media player and VLC after running PE10. If I re-install the graphics drivers I can play the .MTS files from my Sony DSC-HX5 in Windows media player absolutely fine. If I run PE10 then close it again the .MTS files play dark red in media player. These are .MTS files that have never been edited by PE10. I suspect that PE10 is altering my graphics settings in some way. How can I stop this happening please?
I've never heard of this before. But first thing to always do is manually go to Windows Update and look for optional updates. (Critical ones should apply automatically.) Ensure you have all non-critical updates. They sometimes include important drivers and updates.
Though since this doesn't seem to happen with all video -- just the video from this camera --- I'd suspect the codec at work in your cam may be part of the issue.
This is, after all, not a camcorder. It's a still camera. So the video you pull from it does not use traditional camcorder codecs. The specs do claim that it shoots in AVCHD when shooting 1920x1280 30 fps. Is this the mode you shot in?
Meantime, if the camcorder came with any software, make sure to install that on your computer, as it may install some drivers and codecs that may also resolve this issue.
The first thing that jumps out at me is that 23GB of free-space on your C:\. PrE needs about 30- 40GB of free space, just to run efficiently.
Next, a Duo-Core CPU will struggle decoding H.264 material for playback in PrE.
Is your Win7 32-bit, or 64-bit? If the latter, then the 4GB of RAM is about the minimum just to run a 64-bit OS. Also, with 4GB RAM, you will likely be using quite a bit of HDD space just for the Page File (Windows Virtal Memory), and if dynamically managed (the default), then about all of your HDD free-space can be used up quickly.
Why the video driver's update is not "sticking," is a mystery.