special characters in a variable assistance

Question

I'm trying to make a reg query a variable. I can get it to work in win10 but when I try XP it doesn't work. Its a reg query to determin .net4 installed.

set "net4=REG QUERY "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP" | find /i "4.0" > NUL || ".NetFx40.exe" /passive /norestart"

to test on win 10, if I change 4.0 to 5.0 the installer starts, leave on 4 it skips as expected.

On XP as soon as it hits the setting variable element it just tries to install regardless that it's already installed. I'm guessing the pipes and things are breaking the entry, how can I resolve this, thanks.

Answer 1

这是J.Baoby建议的工作方式 ：

set net4=REG QUERY "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP" ^| find /i "4.0" ^> NUL ^|^| ".NetFx40.exe" /passive /norestart