File Redirection using driver (fsredir)

Here is my File Redirection (fsredir) that I write to solve problem with WinPE 3.0
This driver also works on normal windows.

This is my first driver and it is based on Simrep Minifilter Sample by Microsoft.

Download Here: http://www.fileserve.com/file/QCMUp3c
(Tested with windows 7 and WinPE 3.0 only)

Forum post: http://www.boot-land.net/forums/index.php?showtopic=12289

What does file redirection do?

To answer this, lets see what is WinPE:
Windows PE is a lightweight version of windows and was originally to deploy windows but useful to create rescue disk too. Not everything we have in windows is included in WinPE and it will fail to load some applications. Example is application that was written and compiled with VisualBasic 6.0 depends on msvbvm60.dll but msvbvm60.dll is not included and missing from WinPE. We can simply inject all dependencies and dlls into WIM Image but side-effect is the wim image will getting larger and larger and will give you error Ramdisk device creation failed due to insufficient memory.

This is because WinPE create a new ramdisk and put all wim image contents into ramdisk with drive letter x:\. We simply want to keep Wim image small so it will fit into memory and other application can use the rest of unused memory. Here how fsredir help us:
Instead of storing file into wim image, we can simply use our pendrive/harddisk/etc to store file outside the image while WinPE still thinking our file is in x: drive

• When computer boot/or new media storage device attached, fsredir will find fsredir.marker on each device root directory and load it when found. Lets say your fsredir.marker is located on E:\fsredir.marker
• The content of fsredir.marker represent the location of x:\ in your device. It can be blank or changed. Lets say fsredir.marker contain this: \MyWinPe
• When for example, application tried to load x:\windows\system32\msvbvm60.dll but file is not there, fsredir will try to search msvbvm60.dll on your drive which contain fsredir.marker in E:\MyWinPe\Windows\System32\msvbvm60.dll. If your fsredir.marker has no content. It will search in E:\Windows\System32\msvbvm60.dll
  
• If fsredir found the file, it will redirect the request to open that file into new location.
• Your application load :)

Installation (Inserting the driver into wim image):
1) Inserting the driver into wim image:

• Download the driver above and Extract all the content into new folder
• Mount your wim image by using imagex or dism (eg imagex /mountrw PATH_TO_WIM 1 PATH_TO_MOUNT_DIR) Lets say PATH_TO_MOUNT_DIR is C:\WinPE\Mount\ (Tutorial can be found here or search using googles)
• Copy \file\fsredir.inf to C:\WinPE\Mount\Windows\inf
• Copy \file\fsredir.sys to C:\WinPE\Mount\Windows\system32\drivers
• Copy \file\fsredir.marker to your pendrive or other external drive (outside, not in folder or subfolder)

2) Installing the driver

• Open regedit.exe as administrator
• Click HKEY_LOCAL_MACHINE and goto menu File\Load Hive
• Browse and open C:\WinPE\Mount\Windows\System32\config\SYSTEM
• Name it as WINPE
• Double-click fsredir.reg
• Click HKEY_LOCAL_MACHINE\WINPE and go to menu File\Unload Hive
• Close Registry editor.

3) Modifying fsredir.marker and add files

• By default, fsredir.marker contain \fsredir, you can change this to other path that will be merged with x:\, make sure to include slash \ in front of the path
• Example to put files into system32 folder
• If your fsredir.marker contain a path (e.g. \fsredir)
• Create a new folder in pendrive and name it fsredir. Open the folder and make a new folder windows and open your windows folder and create a new folder again and name it system32 (?:\fsredir\windows\system32)
• Now you can start copying files into \fsredir\windows\system32\ folder
• If you want to put your files in other path, you can simply change in fsredir.marker

Installing driver in normal windows:
Installing this driver in windows is easy.
Copy fsredir.marker to appropriate location and right-click fsredir.inf and choose Install.

Limitation:

• FindFile API will not list the redirected files