Sometimes an EPS file will download with the extension.ps rather than .eps. Unfortunately, this makes it impossible for your PC to read the file. To fix this, simply change the extension:
Right-click on the filename.
Insert an "e" between the period and the "ps".
Hit the Return key.
This should solve the immediate problem. When you download EPS files in the future, keep an eye on the "Save As" field in the "Save As" dialog box, and insert an "e" between the period and ".ps" if it's left out.