5. Appendix

Here you can find additional support for WMI. You can find information that will help you with troubleshooting issues, finding answers to common questions, and exploring further resources to gain a better understanding of Windows Manual Installer.

Troubleshooting

If you're here, you must need a way to know more about problems with WMI.

We'll start off with common errors that you can experience while using WMI.

Common errors

"Not a recognized argument"

This one's an easy fix. If you want to start WMI Rollback, invoke it with the below command:

> wmi.exe -rb

or with:

> wmi.exe /rollback

If you instead just want to run WMI, you need to run it without any command line argument like so:

> wmi.exe

"Not running from Windows PE"

This happens if you're running WMI on your actual computer, and not inside of the bootable Windows installer.

"You need to run WMI with admin privileges"

This error is caused by the fact that WMI might have started with standard privileges instead of administrator privileges. This shouldn't happen though, this check exists for safety purposes only.

"The C letter is already assigned to another drive"

This one's an easy fix too.

You just need to press Enter and choose another letter to install Windows to.

This letter will be restored to C after Stage 0 completes.

(You don't need to think that much about it: just hit the first keyboard key you see and you'll be ok)

NOTE: Please be aware of this problem right here.

Known problems of Version 0.5.0

Although this version is the first ever stable version of WMI and the C++ port brought many positive things to WMI, it's also been a significantly big change in terms of the application structure itself. I'll list all the problems that came up when porting WMI to C++:

• You can only select disks whose numbers are 0-9

  The disk selection prompt is built in such a way that it is almost impossible to break, but at the same time it brings some limitations. Since the user input is got by the getch() function, it means that the input can only be 1 character long. More specifically, the disk number cannot exceed the two-digits limit, as it would be impossible to select it.

  But it shouldn't be that much of a concern in most cases - usually we don't have that many disks in our computer, plus it's very rare to see them assigned to two-digits numbers. Fixed disks usually sit in the first 10 places, the first being 0 and the last being 9.

• INDEX value cannot exceed 9

  For the same exact reason, the two-digits limit applies to the INDEX selection prompt as well. In this case though, the thing is much more limiting as many Windows ISO files get bundled with lots and lots of editions, up to 13 in a single ISO file. You can only mark for installation a Windows edition whose INDEX value is between 0 and 9. Any Windows edition whose INDEX value is greater than 9 (therefore being two digits long) cannot be selected.

  Usually though, INDEX values above 9 are for Windows Pro N for Workstations, Windows Pro Education N and similar editions.

• You shouldn't press special keys when selecting the new letter

  That's not an actual problem, but that's right: if you are at the point of the setup where you need to select another letter because the C is already taken and you try pressing special keys (for example DEL ), the prompt will detect the ASCII character assigned to that key.

  Let me give you an example. Let's say you're at the letter selection prompt, and you press DEL (maybe by mistake). What will happen is that the current codepage (850) will assign an ASCII character to the DEL key, therefore inputting the assigned character for that key.

  More specifically, the character assigned to the DEL key is ÓS. When parsing the input, the Ó character will be skipped (as it's not a recognized letter), but the S character will be kept, therefore selecting S as the new letter.

  This applies to every function key (DEL, END, PGUP, PGDOWN) and to every NUMPAD key (when NUMLOCK is off).

• You shouldn't select your WMI USB as the target disk

  If you are at the disk selection prompt and you select the USB on which you placed WMI, that drive will be formatted, therefore wiping out WMI while still running.

  This will call WMI Rollback with the INT_WIMFILE_NOT_FOUND interrupt code, but as soon as you press Enter, a The system cannot find the path specified. message will be displayed several times, which will prevent your USB drive from being properly formatted.

  

  To make it usable again, you need to connect it to your computer and follow these steps to format it:

  • First, open up a command prompt window and run the following command:

    > diskpart

  • Once DISKPART has loaded, run this command:

    > lis dis 

    You'll need to locate the number of your USB drive, then you can proceed by running:

    > sel dis yourDiskNumber

    (replace yourDiskNumber with the actual number);

  • Then, you need to execute the following commands one-by-one:

    > cle
    > cre par pri
    > for fs=exfat quick
    > ass letter=letterOfYourChoice
    > exit

    (replace letterOfYourChoice with an actual letter, after you made sure that letter is not taken by another drive. You can try with letters at the very end of the alphabet, they will pretty surely be available);

  And you're done. Your drive is now usable again.

• Your username cannot contain special characters

  When you're at the point of having to choose a username, you better take the following into consideration:

  The user account is created using the NET command. One of its arguments needs to be the actual username.

  The Windows command prompt has a list of characters that are interpreted as operands, and <,>,\,|,/,@,[,],* are some of them.

  Putting those characters in your username would cause the CMD to perform the corresponding action, therefore skipping the creation of the user account.

  You can however use them in your password without concerns.

  If you accidentally put any of them in your username, you'll see this screen when trying to login to Windows:

  

  It means that no user is available on the system.

  The only way to fix it at the time of writing this is this one:

  • First, press five times the Shift key on your keyboard. This will bring up an elevated command prompt.

    

  • Run the following commands, one at a time:

    > net user /add "yourUsername" "yourPassword"
    > net localgroup /add Users "yourUsername"
    > net localgroup /add Administrators "yourUsername"

    (replace yourUsername with an actual username, make sure to keep doublequotes around it. If you want, you can omit the "yourPassword" part);

    NOTE: You may see some errors between each command, just don't care. Windows is just not clever enough to realize that the new user account is being created right now.

  • Close the CMD window.

You should then be able, by entering your username and password, to login to Windows.

References

Glossary

Windows Manual Installer Post-Install Utility, also referred to as the WMI WPU or just the WPU.

Windows Manual Installer Rollback, mostly referred to as WMI Rollback.

Credits

https://www.youtube.com/watch?v=JxJ6a-PY1KA - the video from which I got the inspiration to build this whole WMI crap.

https://massgrave.dev/ - MAS author.