The exclamation point isn't exclusive to updates. HP Support Assistant also works with Windows Security Center to share status updates.
If you did not see a category with the exclamation point upon opening HP Support Assistant, you may need to try uninstalling and reinstalling HP Support Assistant. This can be done with the download from the following site.
http://www8.hp.com/us/en/campaigns/hpsupportassistant/hpsupport.html#.Ufloa21t7AY