What are your Project settings, chosen at New Project?
What are the pixel x pixel dimensions of your Still Images? If much larger than the Frame Size of the Project, then there can be real issues with performance.
How many Still Images are we talking about here?
What is the format of the Still Images?
Pentium (R) 4 CPU 2.80 Ghz... 2.79 GHz, 504 MB Ram
A Pentium 4 with only a half a Gig of ram is BARELY going to be able to edit SD material... not likely to edit HD at all
You do not mention hard drives, so I will GUESS you only have one... which is not going to work very well
Photo Scaling for Video http://forums.adobe.com/thread/450798?tstart=0
-Too Large = Crash http://forums.adobe.com/thread/879967?tstart=0
My 3 hard drives are configured as...
1 - 320Gig Boot for Win7 64bit Pro and all program installs
2 - 320Gig data for Win7 swap file and video project files
3 - 1Terabyte data for all video files... input & output files (*)
(*) for 4 drives, drive 3 all source files & drive 4 all output files
Search Microsoft to find out how to redirect your Windows swap file
Trying to use only ONE Hard Drive for Video Editing
You are a music conductor, with a baton that you use to point to various parts of the orchestra... this is like Windows pointing to various parts of the hard drive to do Windows housekeeping or to load program segments for various functions
Now, at the same time and with the same hand... while still using the baton to conduct the orchestra... pick up a bow and play a fiddle... this would be doing something with your video file at the same time as all the other work
You as a person cannot do both at the same time with the same hand
A computer is a LITTLE better, in that it can switch from one kind of task to another very quickly... but not quickly enough for EASY video editing
You need AT LEAST two hard drives (separate drives, never a partition http://forums.adobe.com/thread/650708?tstart=0 for more) with Windows (or Mac OS) and software on your boot drive, and video files on a 2nd drive so the boot drive is not slowed down by trying to do everything
I find that the three drives I use work very well for me, for editing AVCHD video... some people use a 4th drive, so video INPUT files are on drive three and all OUTPUT files are on drive four... I only bought a mid-tower case instead of a full tower case (my bad... but had to fit in the space available on my office desk!) so I use the three drives that will fit
Depending on your exact hardware (motherboard brand & model AND USB2 enclosure brand & model AND external hard drive brand & model) AND the type of video file, you may... or may NOT... be able to use an external USB2 hard drive for SD (Standard Definition) video editing
Steve Grisetti in the Premiere Elements forum http://forums.adobe.com/thread/856208?tstart=0 and Jim Simon in the Premiere Pro forum http://forums.adobe.com/thread/856433?tstart=0 use USB externals for editing
A USB3 hard drive connected to a motherboard with USB3 is supposed to be fast enough for video editing (I don't have such, so don't know) but eSata DOES have a fast enough data transfer for video editing... I have not used this eSata Dock... for reference only, YMMV and all the usual disclaimers