Yesterday, one of my clients came across an interesting scenario. They use FTP to poll sales data from their retail outlets back to a central location. As part of this process, the polling file is renamed to filename.bak; but what if filename.bak already exists from an earlier poll? The existing NT 3.51 FTP Server network component allows the rename with no problem, but XP’s FTP Server (part of IIS 5.1) does not, producing an error:

550 filename.bak: Cannot create a file when that file already exists

A quick search on the ‘net unearthed Microsoft knowledge base article 309634 . Once I had extracted the mdutil.exe utility from a Windows 2000 CD (see Microsoft knowledge base article 240225) I was able to run the following command:

mdutil set msftpsvc/1/AllowReplaceOnRename 1

A restart of the IIS Admin service was all that was needed then to allow the rename to take place within the polling process.