Have you had enough privilege to install the driver? Also can you try to install NDIS IM driver manually for the case if something went wrong with snetcfg utility:
Prepare a floppy disk (or installation directory) that contains these files: ndisrd.inf, ndisrd_m.inf and ndisrd.sys. On the desktop, right-click the My Network Places icon and choose Properties. Right-click on the relevant Local Area Connection icon and choose Properties. Click Install, then Service, then Add, then Have Disk. Browse to the drive/directory containing the files listed above. Click OK. This should show “WinpkFilter Driver” in a list of Network Services. Highlight this and click OK. This should install the WinpkFilter driver. Click OK or Yes each time the system prompts with a warning regarding installation of unsigned files. This is necessary because binaries generated via the DDK build environment are not signed. Two .INF files are needed rather than one because WinpkFilter is installed both as a protocol and a miniport.
This is not a usual case as WinpkFilter does not have any known issues with Windows XP SP3, most probably something has prevented driver from being installed.