Tom,
The requirements as stated in the requirements page for PixInsight says the following:
Video Hardware
Minimum required video mode: 1024×768, 24-bit true color.
Minimum reasonable video mode: 1280×1024, 32-bit true color.
Minimum recommended video mode: 1680×1050, 32-bit true color.
Recommended performance video modes: 2560×1440 / 2560×1600, 32-bit true color.
We strongly recommend a high-end 27-inch or larger LED/LCD panel, or two panels driven by a dual-head video card. For serious image processing, working with large monitors is a real must with PixInsight.
http://www.pixinsight.com/sysreq/index.htmlI went and tested this on my computer which I am running Windows 7 also. I had no problem with the mouse over help menus. I tested at my normal 1920x1080, at 1280x768 and at at 1280x768 with a high DPI for the font display. Here are the screen captures.
You might want to check and see if your display driver and monitor driver is up to date.
Mike