Windows Logon displays the following Logon Message in a box:
“The system cannot log you on due to the following error:
The program issued a command but the command length is incorrect.
Please try again or consult your administrator”.
What I found is that the problem is caused after you have downloaded some Windows Update that may be also a malware or a spyware. So you just need to uninstall the update.
• For some it was the update like KB885835 or KB914882 (might differ for you). Uninstall updates in the reverse order of which you installed and for that check the date/time stamp, not the number.
• But for that you need to login to the system (that is what is the problem, right?)
• For that, you can either boot the system with the Windows CD or connect the drive to another machine as a secondary drive.
• Now go to \windows\$NtUninstallKB914882$ (hidden by default) or whatever number you are trying to remove. Delete the folder. If the same update is present in Add or Remove Programs in Control Panel then uninstall it from there as well.
• Let’s hope the error is removed after reboot.