Problems starting Gnucash under Windows 7

[Michael]

Hallo,

we recently upgraded a number of computers to Windows 7 (32 bit, SP 1)
after formatting the hard disks and could not start the newly installed
Gnucash on any of them. After installing Gnucash 2.6.10 the opening
screen popped up once in a flash and disappeared. Going back to an older
installation file (2.6.5) which runs on another computer under Windows
10 without problem ended with the same result. In the net I found the
proposal to run Gnucash as administrator. This didn't solve the problem.
Two out of the three tested computers are on-line, one off-line. The
on-line machines are protected by Kaspersky, the off-line machine has no
anti-virus installed.
We switched the whole accounting of our Association for Autism to
Gnucash and are now in trouble as we can't get it running on the
accountants computer.
So any help is highly appreciated.

Best regards,
Michael