[modeller_usage] FATAL ERROR: MODINSTALL9v01 environment variable not set: incomplete MODELLER installation.

Dear Modeller users and administrators, this is not for the first time I experience difficulties with Modeller installation. On Notebook, NetBook and two PC I ve got same problem, which hasn t disappeared after restart. Operational systems: Windows XP, Windows 7.

FATAL ERROR: MODINSTALL9v01 environment variable not set: incomplete MODELLER installation.

What can cause such error?

Sincerely yours, Andrey