The first thing to check is to make sure Photoshop was closed during installation of the plug-in. If not, simply restart Photoshop. Once Photoshop is open, please go to Window > Extenstions > onOne
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This will open the onOne panel giving you access to your product. Just open an image in Photoshop and choose your plug-in [...]

Please note that there is an incompatibility with the Windows version of Photoshop CS4 and the onOne menu. When installing any of these updates for Windows Photoshop CS4, the onOne menu may not be present, as you have seen in the past. If you do not see the onOne menu, you can access the plug-in [...]