Hello and thank you for the post.
This is disappointing for sure, could you try the following for me?
Ensure both PicoScope versions are uninstalled (Beta and Stable)
We then need to delete the contents
of the following folders Windows XP
: C:\Documents and Settings\<User name>\Local Settings\Application Data\Pico Technology\Windows Vista/7/8
: C:\Users\<User name>\AppData\Local\Pico Technology\
The example below is for Windows 8
Could you then locate the the folders in the images below?
I would like you to delete the contents
of these folders (Not the folders themselves)
Could you then try to reinstall the stable version only?
Should the install prove unsuccessful, could you create an install log file and send these over to firstname.lastname@example.org
To create an install log file please take a look here at topic10701.html
Sorry for all this additional work but we will resolve this for you