[Petya V4sechkin]

Toltec, простейший вариант:

Код:

@Echo Off
SetLocal EnableExtensions

Set Copied_1=
If Not Exist %windir%\system32\1.dll (
  Copy 1.dll %windir%\system32
  Regsvr32 /s %windir%\system32\1.dll
  Set Copied_1=1
)
Start /Wait proga.exe
If Defined Copied_1 (
  Regsvr32 /u /s %windir%\system32\1.dll
  Del /Q %windir%\system32\1.dll
)