Filters won't load.

[Diamonds]

I opened Photoshop today and I noticed that some of my filters won't work. The ones that I downloaded myself and also the ones that already come with Photoshop show up on the list but they are gray and I can't click on them. Another thing is, I don't have as many file extension options to save my graphics as like I did before. Such as .png, .gif. Some of those are missing. I tried to increase the amount of memory Photoshop uses but that didn't work. Can anyone help? I need to make a graphic for someone but one of the filters that I use to do that won't work.

[uniqueangel]

urm try this , Disk Defragmenter, Disk Clean up, Check for virues on your computer. or restart your computer if not you may have to reinstall ps again.