For BartPE based on 2003 this works - add this as plugin - do not use regular procedure.
Archive is attached
Result:
; PE Builder v3 plug-in INF file
; http://www.nu2.nu/pebuilder/
;
; vmxnet2and3.inf
; for vmxnet2 and vmxnet3
; Created by Sanbarrow
[Version]
Signature= "$Windows NT$"
[PEBuilder]
Name="vmxnet2and3"
Enable=1
[SourceDisksFiles]
files\vmxnet.inf=20,,1
files\vmxnet.sys=4,,1
files\vmxnet3n51x86.sys=4,,1
files\vmxnet3ndis5.inf=20,,1
attached files: vmxnet2and3.zip