More details, please. Do you use Quicken Mac or Quicken for Windows? US or Canadian version? What version, edition level and release of Quicken are you using? Click Help / About Quicken (Mac: Quicken / About Quicken) to get this information. What version of Windows or Mac OS are you using?
If you haven't rebooted Windows since you installed the latest software update, please do so now and then try Quicken again.
Still not working?
Please perform the steps in this document:Troubleshooting 101 - Fixing Software Installation and Data File Problems