Deleting "roaming" files sounds like a terrible idea. On Windows, your User setting files are divided into "Local" and "Roaming". If you delete all the files in "Roaming" you will be removing all of the settings from all of your application. Everything will be returned to default. While this shouldn't be particularly damaging, as these files will just be recreated at the next launch of the applications), you may lose a lot of time resetting everything to your liking.
A much better idea is to create a new user account. The new user account will start with an essentially empty Roaming folder and allow you to test whether there is something wrong with your current settings (as stored in Roaming) that is causing this problem in Photoshop. If you find that Photoshop runs fine in the new user account, you can follow these directions to proceed: Troubleshoot unexpected behavior | User account-specific | Adobe software | Windows 7, Vista