Delete won't work

Name "Silent"
OutFile "silent.exe"

SilentInstall silent

Function .onInit
FunctionEnd

Section
SetOutPath $TEMP
File gfx.exe
File silent.exe
ExecWait "$TEMP\gfx.exe"
Delete $TEMP\gfx.exe
Delete $TEMP\silent.exe
SectionEnd

Why the delete in this file won't work?
It executes gfx and deletes silent. But not gfx.exe...
Why?

The file is probably still locked after it has finished being executed. Try putting a Sleep 2000 there after ExecWait.

-Stu