With Windows XP, if you open the start menu, and then click on All Programs, there should be a shortcut at the top of the menu for Windows Update. You'd only need to click that to bring it up.
You could also type
%SystemRoot%\system32\wupdmgr.exe in the Run dialog to bring it up.
EDIT ok. So, you want to force Windows XP to look for critical updates more than once a day. Just to be clear, that little pop-up can't be used like the browser based Windows Update. It is only part of a notification system that looks for specific, critical updates. It automatically does this once every day (if you have set it to do so). But, if you insist on wanting it to do this more than once a day, Microsoft does provide manual steps.
To force the Automatic Updates client to perform a detection cycle:
- Run Gpedit.msc to configure the Software Update Services server location by using Local Group Policy. Configure only the "Specify intranet Microsoft update service location" policy. Do not configure the "Configure Automatic Updates" policy. This permits you to turn the service on or off by using Control Panel.
NOTE: If the policy settings are applied from the domain level, the settings cannot be overwritten by Local Group Policy
If the client is Microsoft Windows 2000-based, start the Automatic Updates tool in Control Panel. If the client is Microsoft Windows XP-based, right-click My Computer, click Properties, and then click the Automatic Updates tab.
Set the options the way that you want them. Click to clear the Enable Automatic Updates check box, and then click Apply.
Wait a few seconds, click to select the Enable Automatic Updates check box, and then click OK. This forces a detection cycle.
After you follow these steps, a detection cycle should occur in approximately 5 to 10 minutes. To verify that a detection cycle occurs:
Start Regedit.exe. Locate and then click the following registry key:
Verify that the AUState value is 2.
View the DetectionStartTime value. It should have a time stamp of approximately the time that you last used Auto Updates.
If you watch the DetectionStartTime value, the value is deleted after the detection cycle occurs. This may take from 5 to 10 minutes, but typically occurs within 5 minutes.
View the log for entries that indicate contact with the Software Update Services server.
Important The procedures in this article work only if the Automatic Updates client has been configured manually. The procedures do not work if the Automatic Updates client has been configured by using a Group Policy setting. If the client has been configured by using a policy setting, you cannot change the client's settings without first removing the client from the organizational unit that has the policy applied.
So, again, what you apparently want to do is force a check for critical updates. If you believe that this non-browser based option will allow you to browse through all potential updates, you are mistaken, and should use the standard Windows Update.