The current templates that come default with Zabbix causes some machine agents to hang:

perf_counter[\Physical Disk(_Total)\Avg. Disk Read Queue Length]
perf_counter[\Physical Disk(_Total)\Avg. Disk Write Queue Length]

The correct perf_counter is (Note the lack of space between Physical Disk)

perf_counter[\PhysicalDisk(_Total)\Avg. Disk Read Queue Length]
perf_counter[\PhysicalDisk(_Total)\Avg. Disk Write Queue Length]

Even though this returns successfully on versions greater than Windows 2000 SP4, it still causes the agent on 2K SP4 to hang.