You are very welcome.
Yes. I understand what you are trying to do. With these newer iVMS versions you can have a maximum of 50 different user accounts per iVMS system. Not sure how many you need.
I have not changed Netinfo while using a NVR ("Don't have/use a NVR") so I can't emulate your environment for testing and have no suggestions other than to say try it and set it back if it fails.
You can find a .pdf users manual for the iVMS version installed in the program files folder for your Windows system in the iVMS folder as well as under you Windows "All Programs" on your desktop there is a link to the iVMS users manual and there is a log subfolder in the iVMS folder in your Windows program files folder. Which has client log data in plain text that maybe helpful to review to try and determine why the install is failing on one system and not the other.
I do know that there are some 64 bit Windows enhancements in the newer iVMS English version shown below.
As far as the system that's failing. There are newer versions of iVMS available that incorporate the blending of admin permissions on the somewhat older version of iVMS you are using. So you could try the newer iVMS version on the current system that is failing if you wish.
There are currently two newer versions of iVMS newer than iVMS v2.02.00.04. One is a multi-language release and the other an English release.
Note: IMHO, if you don't need multiple languages. I'd use the English release since it also a newer release than the multi-language release. Also, the English release simply has a "Quit" permission that you can assign to a user account at user account creation or modification time.
More details:
Hikvision iVMS-4200 v2.02.03.03 (Windows, multi-language)
http://www.hikvision.com/europe/download_more.asp?id=1440
Hikvision iVMS-4200 v2.03.00.05 (Windows, English)
http://www.hikvision.com/europe/download_more.asp?id=1462
Don