How can I force a machine to check in with the WSUS server?

I am trunning WSUS 3.1 on Server 2003 and the console says that a machine' last status was 2 hours ago. How am I suppose to force a machine to check in with the WSUS server? Thanks

It is very simple, just try to Run - wuauclt.exe /detectnow on client machine and you are good to go on.

So, I ran wuauclt.exe /detectnow on the client about 10 minutes ago, but still the machine is not shown in the console. Also, I am not able to see its update status and the client diag tool reports no failures?

Edit:
I am not able to see that the machine has successfully updated its status, thanks.

That seems to have happen at a fast rate for you, because other users normally had to wait for about 35 minutes or so to see the result.

When ever a local admin logins, whether on windows xp or windows server 2003, they normally get a notification saying that there are some updates that are available for download and by downloading it they could initiate this pending status. After that, once all the downloads are finished, they will also get notification pending for the updates to be installed on the machine and they should then intiate the installation procedure. But on Windows Vista or Windows 7 and later on OS'es, any user who is logged on can go to control panel and initiate a download or installation from the windows update if there are updates pending.