Why is it taking so long for my imovie to repond

Are you using the multi-touch trackpad or a separate mouse (Bluetooth/USB)?

Does the problem only occur when in iMovie?

What are you attempting to do when this happens?

Just trying to get some more information to further assist you, thanks.

Thank you.

Does this only happen with a particular project or does this happen throughout the entire iMovie application?

https://discussions.apple.com/thread/3516989?answerId=17407486022#17407486022

This link may help. I do understand that your iMovie is not "crashing" but instead having trouble removing projects, but the solution of removing the .plist file is pretty universal and may help.

Will it even open a project?

If not, your project library may be corrupted.

Alright, just to get that one project out of the way, lets go to the source of the project.

Open a Finder window and navigate to

"Username" > Movies >iMovie Projects > "Your Project.rcproject"

There you will be able to delete the Original file.

If you need to "Force Quit" the application, press the keys CMD + Option + esc, then select the application to quit.

If by force quit, you mean resolve the problem with iMovie freezing, I am sorry I do not know. The only thing left that I can suggest is to reinstall the application.

I do not want to have you running in circles, but maybe you should check the status of your hard drive to verify that system files are not corrupt.

If you choose to do so,

http://support.apple.com/kb/HT1782

(I perform this often, and find that it improves overall performance of my computers)

I am sorry, that link did not explain correctly how to perform the verify and repair.

Open the Utilities folder in Applications and select Disk Utility.

Select your top-level drive and find "Verify Disk".