The new MSU format doesn't support the old /x type switches to extract the content. It also can't be run on a pre-Vista OS. To extract the content from an MSU file, you need to use the Expand command that's part of Vista. Note that the Expand command from earlier versions of Windows are different and won't work. Use the -F switch to extract the content, as the following example shows:

D:\temp>mkdir msu 
D:\temp>expand -F:* Windows6.0-KB929761-x86.msu d:\temp\msu
 
The command produces the following output:
 
Adding d:\temp\msu\WSUSSCAN.cab to Extraction Queue Adding d:\temp\msu\Windows6.0-KB929761-x86.cab to Extraction Queue Adding d:\temp\msu\Windows6.0-KB929761-x86-pkgProperties.txt to Extraction Queue
 
Adding d:\temp\msu\Windows6.0-KB929761-x86.xml to Extraction Queue
 
Expanding Files ...
 
Expanding Files Complete ...
4 files total.
 
At this point, the .cab files, which contain the actual files, are still not extracted, so now run the extract command on the cab file, as the following command and resulting output shows:
 
D:\temp>expand -F:* d:\temp\msu\Windows6.0-KB929761-x86.cab d:\temp\msu
 
Adding d:\temp\msu\update.mum to Extraction Queue Adding d:\temp\msu\x86_microsoft-windows-
wusa_31bf3856ad364e35_6.0.6000.20496_no
ne_ab489c6034d78613.manifest to Extraction Queue Adding d:\temp\msu\x86_microsoft-windows-
wusa_31bf3856ad364e35_6.0.6000.16400_no
ne_ab1a4f0b1b764fed.manifest to Extraction Queue Adding d:\temp\msu\update-bf.mum to Extraction Queue Adding d:\temp\msu\x86_microsoft-windows-
wusa.d_31bf3856ad364e35_6.0.6000.20496_
none_4632ef2815ba2cfd.manifest to Extraction Queue Adding d:\temp\msu\x86_microsoft-windows-
wusa.d_31bf3856ad364e35_6.0.6000.16400_
none_4604a1d2fc58f6d7.manifest to Extraction Queue Adding d:\temp\msu\update.cat to Extraction Queue Adding d:\temp\msu\update-bf.cat to Extraction Queue Adding d:\temp\msu\x86_microsoft-windows-
wusa_31bf3856ad364e35_6.0.6000.16400_no
ne_ab1a4f0b1b764fed\wusa.exe to Extraction Queue Adding d:\temp\msu\x86_microsoft-windows-
wusa_31bf3856ad364e35_6.0.6000.20496_no
ne_ab489c6034d78613\wusa.exe to Extraction Queue
 
Expanding Files ....
 
Expanding Files Complete ...
10 files total.

Source:→ WindowsITPro

Microsoft, Windows Vista, How To, Extract, Files, MSU, Microsoft Update Standlone Package