In a previous blog here I described how to inject VMware pvscsi and VMNET3 mass storage drivers into your Windows Server 2008 or Windows 7 p_w_picpath. However, that did not cover injecting the same drivers into the Windows Recovery Environment, which is a separate WIM within the install.wim, thus requiring extra work. Here's how to inject drivers into the winRE.wim file and repackage the install.wim with the updated recovery environment.

1. Follow the first five steps at my blog here to install WAIK, find the right drivers, and create a scratch directory.

2. Mount the install.wim file from your Windows installation DVD:
dism /Mount-Wim /WimFile:D:\install.wim /Index:1 /MountDir:D:\mount

3. Copy the winRE.WIM to a working folder:
copy D:\mount\windows\system32\recovery\winre.wim D:\

4. Create another mount directory, D:\Mount2, then run this command:
dism /Mount-Wim /WimFile:D:\winre.wim /Index:1 /MountDir:D:\mount2

5. Inject the pvscsi and VMXNET3 drivers:
dism /p_w_picpath:D:\mount2 /Add-Driver /driver:d:\drivers\pvscsi.inf
dism /p_w_picpath:D:\mount2 /Add-Driver /driver:d:\drivers\vmxnet3ndis6.inf

6. Unmount the winRE p_w_picpath:
dism /unmount-wim /mountdir:d:\mount2 /commit

7. Copy the modified winRE.wim file to:
D:\mount\windows\system32\recovery\

8. Unmount and commit the changes to the install.wim:
dism /unmount-wim /mountdir:d:\mount /commit

At this point you now have a modified install.wim file that you can copy back into your Windows OS ISO. Depending on your install.wim file, you may have multiple operating systems that need to be modified. To do this you would serially mount all OS indexes, inject the new winRE.wim then unmount the p_w_picpath. For a typical Windows Server 2008 R2 DVD, you could have 8 p_w_picpaths that need to be modified to cover all of your bases. So this process can be a bit tedious and would lend itself to scripting.