What kind of processor should I use to boost my desktop dell Dimension E510?

I have a desktop Dell Dimension E510 Pentium 4. I want to edit pictures and movies on it, but it's too slow even after upgrade my memories ram to the max of 4GB, and a SATA hard drive of 32MB, 7200RPM, with a storage of 2TB, it still very slow to work with a program like Adobe Premiere Pro CS5. What kind of processor should I use to boost its power? Thank you for your help.What kind of processor should I use to boost my desktop dell Dimension E510?Depends on what your older motherboard will support. As long as you have newer parts, might as well upgrade the motherboard too so you can have some good processor options. As of right now, your socket might not support much more than the P4 you have now