Moving this discussion to the Photoshop Elements forum.
Please try couple of probable solutions as mentioned below:
1. Close Elements.
2. Launch the Photoshop Elements Welcome Screen and hold down ctrl + alt + shift as you click Editor.
3. Continue to hold the keys until you see a message box asking if you want to delete Photoshop Elements settings file; click Yes. Elements will open with default preferences.
Solution 2: In case any network printer is attached try to launch without network or printer uninstall or make different printer as default.
Solution 3: Try launching with anti-virus off or removing PSE from conflicting list.
On the drive on which you have installed PSE,on my machine it is on C:
Go to C:\Program Files\Adobe\Photoshop Elements 11\Locales\<locale>\Plug-Ins\Import-Exportand you will find twain plug-in. Remove that plug-in from that location and copy it somewhere else. Please note that instead of version 11 you must go to the folder of version of PSE you are using.
Now launch PSE and check if it works.