/i [package] Installs the specified product
/f p|o|e|d|c|a|u|m|s|v p - Reinstalls a product only when a file is missing.  
 o - Reinstalls a product when a file is missing or an older version of a file is installed.  
e - Reinstalls a product when a file is missing or an equal or older version of a file is installed.  
d - Reinstalls a product when a file is missing or a different version of a file is installed.  
c - Reinstalls a product when a file is missing or the stored checksum value doesn't match the calculated value.  
a - Forces all files to be reinstalled.  
u - Rewrites all required user-specific registry entries.  
m - Rewrites all required computer-specific registry entries.  
s - Overwrites all existing shortcuts.  
v - Runs from the source file and recaches the local product.
/a [package] Installs a product on the network.
/x [package] Uninstalls a product.
/j u|m [package] Advertises a product (u is current user; m is all users).
/l i|w|e|a|r|u|c|m|p|v|+|![log file] Specifies the log file and the options you can use.
 i - Status messages  
w - Non-fatal warnings  
e - All error messages  
a - Action startups  
r - Action-specific records  
u - User requests  
c - Initial User Interface (UI) parameters  
m - Out-of-memory  
p - Terminal properties  
v - Verbose output  
+ - Appends to the existing file  
! - Clears each line in the log file  
* - Wildcard. Logs all information, but the use of the v option isn't included. To include the v option, type "/l*v."  
/p [patch] Applies a patch. To patch an installed Administrator image, you should also use the /a switch (i.e., msiexec /p [patch] /a [package]).  
/q n/b/r/f Sets the user interface (UI) level.
   n - No UI
   b - Basic UI
   r - Reduced UI
   f - Full UI
/y   Calls system API DLLRegisterServer to register the module--e.g.,
msiexec /y savill.dll  
/z   Calls system API DLLRegisterServer to unregister a module--e.g.,
msiexec /z savill.dll