Thank you, we were aware of that label in Task Manager, I thought that you have experienced slow start times on your Windows 8...
The User Agent app uses 300 ms CPU and 11.5 MB Disk I/O on startup.
After commenting all the code in the app start call the app it is still using 200 ms CPU and 7.8 MB Disk I/O and it's still being reported as High usage. It's a .NET app, maybe that's the reason.
Looks like there's no way to reduce this further but you can use the PC Monitor Manager settings to disable it if you wish.