What have you tried so far? You didn't actually share very much information, such as version of Ghost and also what you are PXE booting to (eg DOS, WinPE Linux.)
I would suggest that entering the error message into Google is a good place to start. If you need help with this, follow this link:
http://www.lmgtfy.com/?q=Cannot+create+a+File+Preservation+Metadata+File+at+path
I had a look at the first hit and this pretty much answers the most usual issues, so in case the above is not yielding results you can work with, try the following link:
https://www-secure.symantec.com/connect/forums/cannot-create-file-preservation-metadata-file-path-error-40217-hp-2730p-version-115