Edit >> Preferences >> Performance
Then disable GPU acceleration.
That sometimes improves things.
cant do that as it crashes when i try
You can turn off the GPU manually by editing the LR preferences file with a text editor like notepad and changing the line useAutoBahn = true to useAutoBahn = false. You would want to do this with LR not running.
On Windows, the LR prefs file is located here:
C:\Users\--yourusername--\AppData\Roaming\Adobe\Lightroom\Preferences\Lightroom 6 Preferences.agprefs
You might make a backup copy of this one agprefs file to your desktop, first, in case you mess something up.
You will have to use LR5 until you upgrade your computer.
thax working now