Xp_cmdshell With Xcopy Returns 2, Why?

According to the documentation, xp_cmdshell returns 0 if success or 1 if it fails, so I was curious as to why I was getting a return value of 2 when using it with xcopy. So in my t-sql code, if I have something like

@result = master..xp_cmdshell 'xcopy c: est.txt c:Program Files'

The result would return 2. Then if I check if @Result is not equal to 0, it would say their is an error when I am not sure if there was one. I did read on a faq that xcopy expects input from the user, which is normally provided at the command prompt through a return after the command and this behavior can me mimicked by adding "< NUL:" after the command text, which will effectively signal the XCOPY input stream, so the above command becomes:


@result = master..xp_cmdshell 'xcopy c: est.txt c:Program Files < NUL: '

I am still unsure why the @result would return a 2 though?
Also, if I am not going into any subdirectories, is their an advantage of copy over xcopy and vice versa?

If anyone has any info, please let me know, I am using Sql Server 2000.

Thanks in advance,
XaiSoft