This sounds fairly typical, Nagios and Nagios XI are generally a lot more well known to Linux admins in my experience, and in most cases they cannot point and click next, next, finish in their environments. I will give a little run down on popular monitoring techniques for Windows:
NSClient++: I am going to combine a few things under the NSClient++ umbrella as it is an agent with a wide variety of solutions inside. The most common use for NSClient++ Is NRPE monitoring on windows systems, think of it as a NRPE agent, it gives you all the ease of use that NRPE does on Linux inside of a windows environment. It uses a single plain text based configuration file where you define encryption, ports, allowed IP's, and handlers for your plugins. Nearly every non Linux or Linux Software specific plugin found on our Exchange can be used with NSClient++ via NRPE. NSClient++ Also comes with it's own check form called check_nt which makes calls directly to the system bypassing individual plugins that you place in NSClient's plugin directory. These checks are most commonly found on our Windows monitoring wizards as they require very little tinkering from the Nagios side. NSClient++ Also allows for passive monitoring via NSCA, and is as easily configured as NSCA is on the Linux side. Find the link to this application at the bottom of this post.
SNMP: Nagios XI can also be integrated with Windows SNMP checks and traps. I have a document on trap integration with Windows however that is the only document we have at this time for Windows SNMP. All configuration is done through the Windows SNMP Interface and is piped directly to Nagios.
EventLogs: For monitoring Windows Event Logs most people turn to the NagEventLog agent as it provides a simplistic GUI with a point and click interface that allows you to configure event log monitoring passively.
PerformanceCounters: Performance counters are most easily monitored by pairing them with NRPE checks ran through NSClient++, I have set this up numerous times with customers and they are very pleased with the amount of detail you can go into while integrating Windows Perf Counters with Nagios XI. The latest one I helped set up was the "outgoing bandwidth" from the Windows server. You can get very granular with Perf Counter checks as they are nested pretty deep within the system.
NRDS: If you cannot directly reach the Windows system through your environment, or you simply want another solution you can try out NRDSWin, built in house here in lovely St.Paul it allows for passive checking over HTTP, you can even use it for plugin distribution and it is very lightweight
WMI: As far as WMI checking goes you can integrate with either NSClient or agentlessly..word? With check_wmi_plus. Check_wmi_plus allows you to use the built in configuration for deep WMI system calls or even write your own queries giving it the flexibility a Windows Sys admin needs to track down those "Windows Only" issues they may run into.
NSClient++:
http://assets.nagios.com/downloads/nagi ... _Agent.pdf
http://www.nsclient.org/nscp/wiki/doc/about
http://assets.nagios.com/downloads/nagi ... Checks.pdf
http://assets.nagios.com/downloads/nagi ... Client.pdf
SNMP:
Configured using built in Windows SNMP handling.
See "If You're a Windows User" Section-
http://assets.nagios.com/downloads/nagi ... ios_XI.pdf
NagEventLog:
http://exchange.nagios.org/directory/Ad ... og/details
NRDSWin:
http://labs.nagios.com/2012/05/22/nagio ... -nrds_win/
CheckWMIPlus:
http://exchange.nagios.org/directory/Pl ... us/details