ntfs.sys error

[dsg257]

I get so far in creating my oem installation DVD using all the instructions on this site but after so long testing it in virtual pc i get the error cannot find ntfs.sys this file is there , i dont know if it is after i replace a certain customised file this happens or what i changed the winntbbu.dll , SFC_OS.DL_, UXTHEME.DL_ ,HIVESFT.INF files any help would be greatfull