Example:
Server: PVS01
Store Folder Name: D:\PVSStore
Image File List:
W7_Image_Clean_V2.5.vhd (Merged Base file)
W7_Image_Clean_V2.6.avhd
W7_Image_Clean_V2.7.avhd
W7_Image_Clean_V2.8.avhd
To create a new merge based including W7_Image_Clean_V2.5.vhd (Merged Base file), W7_Image_Clean_V2.6.avhd, W7_Image_Clean_V2.7.avhd and W7_Image_Clean_V2.8.avhd, issue the following command:
rundll32 VhdUtil.dll,VhdMerge D:\PVSStore\W7_Image_Clean_V2.8.avhd W7_Image_Clean_V2.5.vhd D:\PVSStore\W7_Image_Clean_V2_New.vhd > D:\PVSStore\merge_log.txt
The benefit of using command line to do the merging is it can give you a debug log that will be useful for troubleshooting purposes, but please remember that it won't update the DiskVersion entry in the database.