UserPreferencesMask

When you take this value in HEX:

and convert to binary:

you can tweak various windows settings:

1. 0 Active window tracking
2. 1 Menu animation
3. 1 Combo box animation
4. 1 List box smooth scrolling
5. 1 Gradient captions
6. 0 Keyboard cues
7. 0 Active window tracking Z order
8. 1 Hot tracking
9. 0 This bit reserved for future use
10. 1 Menu fade
11. 1 Selection fade
12. 1 Tool tip animation
13. 1 Tool tip fade
14. 1 Cursor shadow
15. 0 This bit reserved for future use
16. 0 This bit reserved for future use
17. 0 This bit reserved for future use
18. 0 This bit reserved for future use
19. 0 This bit reserved for future use
20. 0 This bit reserved for future use
21. 0 This bit reserved for future use
22. 0 This bit reserved for future use
23. 0 This bit reserved for future use
24. 0 This bit reserved for future use
25. 0 This bit reserved for future use
26. 0 This bit reserved for future use
27. 0 This bit reserved for future use
28. 0 This bit reserved for future use
29. 0 This bit reserved for future use
30. 0 This bit reserved for future use
31. 0 This bit reserved for future use
32. 1 UI effects

You can change some value from 0 to 1 or 1 to zero.
Then convert back to hex. Set this new value in registry.
Logout user and login again to see the change.