Sorta. It was real pain-in-the-ass to run 2000 as a regular (non-administrator) user. Assuming your software worked at all that way, as even Office 2000 had some issues. UAC was necessary.
It required attention to detail, from a sysadmin / desktop admin perspective, but it was definitely possible and paid dividends in users being unable to completely destroy machines like they could on the DOS-based Windows versions. I put out a ton of Windows NT Workstation 4.0 and Windows 2000 Pro w/ least-privilege users. It was so convenient to be able to blow away a user's profile and start w/ a clean slate, for the user, w/o having to reload the machine.
Sorta. It was real pain-in-the-ass to run 2000 as a regular (non-administrator) user. Assuming your software worked at all that way, as even Office 2000 had some issues. UAC was necessary.