kaibear0203 sophysully That depends on why the game is running slowly at the moment. If the problem is the amount of free space on your internal drive, sure, an external might help. But it's not going to make any difference if the slowdowns are coming from your processor or graphics card/chip. Plus, many external drives are very slow or have slow connections, so you might be introducing another point of failure without improving anything.
If you'd like me to look over your current specs, and make suggestions from there, please provide a dxdiag. Click Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.