What MAY have happened is the Win8.1 update made your graphics adapter driver "obsolete"
What is your exact brand/model graphics adapter (ATI or nVidia or ???)
What is your exact graphics adapter driver version?
Have you gone to the vendor web site to check for a newer driver?
For Windows, do NOT rely on Windows Update to have current driver information
-you need to go direct to the vendor web site and check updates for yourself
ATI Driver Autodetect http://support.amd.com/en-us/download/auto-detect-tool
nVidia Driver Downloads http://www.nvidia.com/Download/index.aspx?lang=en-us
Premiere Elements 9.0/9.0.1 works fine with Windows 8.1 64 bit. But, it will be a 32 bit application running in the 32 bit compatiblity mode of the 64 bit system.
It is only Premiere Elements 10, 11, and 12 that are 64 bit applications running specifically in Windows 7, 8, or 8.1 64 bit.
But your issue appears to be one of display problems. Are you running Premiere Elements 9 as the 9.0.1 Update? Version 9 was distinguished for its display issues more so than other versions. Please install the 9.0.1 Update if you have not already.
The first line of troubleshooting is to assure that you have the latest version of the video card/graphics card driver according to the web site of the manufacturer of the card (or, if more appropriate, according to the web site of the manufacturer of the computer). If the driver is up to date, then delete the Premiere Elements 9.0/9.0.1 Bad Drivers.txt file.
The Windows 8.1 64 bit path to it is
Local Disk C
and in the 9.0 Folder is the BadDrivers.txt file that you delete.
After you close out of there and open a Premiere Elements project, the program will generate a new BadDrivers.txt file and hopefully the problem is gone.
Be sure to be working with Folder Option Show Hidden Files, Folders, and Drives active so that you can see the complete path.
The rationale behind the deletion of the BadDrivers.txt file is found in post 10 of this older thread on the subject
The concept of the BadDrivers.txt file and its indication have been a life saver for many, even for those who have versions of Premiere Elements other than 9.0/9.0.1.
Please review and then let us know the outcome.
Thank you so much for your suggestions
- I found the problem, when installing 8.1 the screen display is changing to a zoom of 125% only needed to change this to 100%.
Thanks for the good news of your success. Great troubleshooting.