Error during Copying files during 64 bit 2K3 instn

[vnykr]

My OS is shared and mapped to Z: (so both AMD64 & I386 are available)

After i trigger winnt32.exe

during copy of files ...i got a pop-up error mesg which looks as follows..

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An error occurred while copying usetup.exe to C:\$WIn_NT.~LS$\amd64\system32\smss.exe

The file is missing. Contact your system admin...etc etc..

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I checked in source AMD64\ for usetup.exe & smss.exe.

Both files exists over there.

What could be the problem?

And

even the error looks even UNEVEN..?

"copying usetup.exe to smss.exe" why windows installer wants to copy one setup file on to other exe.?