WMI check for uptime gives Access Denied

[efiten]

I'm trying to monitor uptime on all of our servers, the ones with RMA installed are ease, I use WMI with the expression " Select SystemUpTime from Win32_PerfFormattedData_PerfOS_System"
But when I use an agent to check this on an other computer (I just alter the target from 'localhost' to '10.0.0.1' or the IP of the host I want to check) I get an 'access denied' error.
The computers are on the same network, same username but different passwords, maybe this is the problem.
Or maybe there is another way of checking uptime on remote computers?

[KS-Soft Europe]

Have you provided user account credentials for remote system using Connection manager (Menu Profiles -> Connection manager...) ?
Is RMA started as Application or Service ?
If RMA started as Service, have you specified user account with admin rights to start RMA service ?

[efiten]

I use it as an application, and just filled in the credentials in the connection manager (never new it existed )

Now I get "RPC not available", but that's not HM related i think.

[efiten]

Now I get "RPC not available", but that's not HM related i think.

I configured the firewall, and it works

[KS-Soft Europe]

Great