Be sure to unblock support@jyotishtools.com if you email us and want a reply.

JyotishTools for Windows

Though JyotishTools for Windows is over a decade old it can still run on newer versions of Windows including 7, 8 and 10. If Windows 10 rejects the keycode then right click on the JyotishTools icon and select Troubleshoot Compatibility. It may recommend a Windows 7 compatibility mode and have you run the program. The keycode should work with that setting. Be sure when prompted to select always running the program in this mode.

However it should be installed by right clicking on setup icon and selecting “Run as Administrator”. This way if you purchase a key you won’t need to re-enter it every time you run the program, which might prove to be a bit annoying.

When purchasing a key don’t use anything other than ASCII for your user name. Though the key generator can generate keys from non-ASCII input the Windows framework used in the program can’t read them properly.


There is a small built-in atlas. At the time many astrologers already had the ACS Atlas and ACS provided a plugin for developers to read from it. That support is still there though it may not work with the version that AstroLabe now sells as the PC Atlas.

Time zones

Back in the day when most astrologers had struggled with calculating charts themselves everyone knew that zones west of GMT (UTC) were positive as in +8.00 for PST and negative for zones east as in -5:30 for India. Newer astrologers who look up zones online will be seeing the opposite because the most general use of time zones is for figuring out the time in a city when GMT is known. We know the time of the location but need the GMT (UTC) time for planetary engine. Hence the opposite values.

Junior Jyotish

Over the years I’ve tried to keep the download for this program small. Originally the installation was not complex and resulted in a small file. More recent builds require a different set of DLLs for to work. Unfortunately Microsoft did not chose to include these DLLs in later versions of Windows. So a few years back I created a “static” version where those DLLs are built in and a simple installer used. However for most computers that killed printing.

So until I can build a version with the complicated installer Microsoft provides the download will not include the required DLLs and instructions will be included as to where they may be downloaded though in some cases they may have been installed by another program.