I am trying to install XP SP3 on a machine at work but I keep getting an error that reads "Setup cannot copy the file setup_wm.exe.  Ensure that the location specified below is correct, or change it and insert 'Windows XP System Files' in the drive you specify.  Copy files from c:\program files\windows media player."

I am using a Dell Optiplex GX520 with Windows XP (currently SP2). 

Does anyone have any suggestions?Check, if your system files are OK...

Go Start>Run ("Start Search" in Vista/7), type in:
sfc /scannow
Click OK (hold CTRL, and SHIFT, hit Enter in Vista/7).
Have Windows CD/DVD handy (with Vista/7, most likely, you won't need it).
If System File Checker (sfc) will find any errors, it may ask you for the CD/DVD (rarely in Vista/7 case).
I would suggest you download the network installation package of Windows XP SP3, as I've found this is the most reliable WAY depending on your internet connection speed, and also you can keep it as backup or use on multiply pcs. It's however a larger overall download.

WindowsXP-KB936929-SP3-x86-ENU.exe (316.4MB)
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=5b33b5a8-5e76-401f-be08-1e1555d4f3d4&displaylang=en

You can use a download manager to help you resume and/or segment download. If it doesn't grab the file at first, simply cancel and your'll get 'If your download does not start after 30 seconds, click here:' appear on the webpage, right click the 'Start download' link and copy the url into your manager.

Ensure it's the correct filesize and fully downloaded.

When running it should VALIDATE its file STRUCTURE and the current OS installed.
Ok ... I tried the scf /scannow.  I got a message that read, "Windows cannot find 'scf'.  PLEASE make sure you typed the name correctly and try again.  To search for a file, click the Start Button and then click Search."Okay,  you need to start by paying attention. The command is sfc NOT scfCopy/paste works always better, than typing by hand.