Hi, mitchnjan!
Microsoft Office 2000 was launched in 1999, which is over 17 years ago! It's seriously outdated, and was sold in a time period where a desktop computer with 4 gigabytes of memory was unheard of.
You are most likely experiencing compatibility issues by running software that is 16 years old than the OS it's running on. Core components of the OS have most certainly changed in the last years, and you're probably getting error messages because Microsoft Office is trying to run commands or load modules that is no longer supported/included or have changed in newer versions of Windows.
I would recommend to upgrade to the latest Microsoft Office release, which is Microsoft Office 2016. It's runs great on Windows 10!
An...