The responsiveness of the scroll bars on an Easy-PC design window is related to the size of the design working area.
The maximum zoom scale is also affected by the operating system. Operating systems based on Windows NT (NT, 2000, XP) allow the software to use a zoom factor 4 times greater than is possible on Windows 95, 98 or ME.
To increase the responsiveness, you need to reduce the overall working area of your design. Use the [Working Area] option on the [Settings] menu, and either choose a smaller working area size for yourself, or choose [Best Fit] to let the program calculate it for you.
Note: this will also have the effect of allowing you to zoom in 'closer'.