Virtual CD/DVD drive problem for install applications

[frezenius]

Hi

I prepare unt.DVD (xp sp2+ office 2k3+ other applications)

Install applications from CD,

I have a problem.

RunOnceEx.cmd:

@echo off

FOR %%i IN (D E F G H I J K L M N O P Q R S T U V W X Y Z) DO IF EXIST %%i:\CD.txt SET CDROM=%%i:

...

...

...

My problem:

I have a generic usb card reader(SD, mcSD, CF ...) in my computer case.(usb cable plug motherboard's usb pins)

When RunOnceEx.cmd running, ALert me "no media in drive M, and N, and O.." (M,N,O...are drive card reader)

or when prepare a test.cmd file for an application installing,

test.cmd:

@echo off

FOR %%i IN (D E F G H I J K L M N O P Q R S T U V W X Y Z) DO IF EXIST %%i:\CD.txt SET CDROM=%%i:

...

...

alert me "no media in drive K (K is virtual drive alcohol 120)

What's wrong?

Please help me and sorry for my english