Regarding scripts..
All your scripts from 3.4 will work in 4.0 because 4.0 was built on the same platform. you need to locate the windower4 files and replace the empty script folder with your original folder from 3.4.
When you initially downloaded 4.0, you had to select a location for the windower4 files. For me, it was C: > Program files (x86) > windower4.
Find this folder and move it to your desktop if you want to. Then replace the empty script and screenshot (if you wish) folders with your folders from 3.4.
After that, everything should be fine regarding scripts.