Fun with xcopy on Windows XP:
"First: Don't use single quotes but double quotes. Single quotes are allowed for file names. Then just omit the closing quotes, and XCOPY works. Or put only parts of the target in quotes: xcopy c:\foo c:\blah\'some odd name'\stuff\ works as well."

You apparently actually can use double quotes around the whole path now, but there's some interaction with xcopy that requires you say what the output file format is.

Anyhow, if you get an error about "Invalid number of parameters" with xcopy, check out spaces in dirs first. I'm glad there's a cmd-line in Windows, but sometimes I wonder how well it's maintained/used at MS. Course Win2k's telnet is cmd-line again... that's nice...