Go to: C:\Users\YourName\.gimp-2.8 to see if you still have the preferences folder. If you are installing Gimp old version, make sure you install the last version of the 2.8 series (2.8.22). But if you are installing GIMP latest version, make sure you re-name the .gimp-2.8 folder to, ".gimp-2.8.old". Otherwise GIMP will migrate all the stuff you have there to the new GIMP 2.10 folder. If that happens, it will cause a lot of problems with older scripts and plugins not compatible with GIMP 2.10. After you install GIMP 2.10.18, then you can move your stuff from the 2.8 folder gradually to see what filters scripts and plugins you can use in the new version.
Good luck!