I'm trying to silpstream sp3 for office using the how-to guide (http://unattended.msfn.org/xp/officexp_advanced.htm). I downloaded the sp3 update and another post sp3 update from the MS website. extracting them i got 5 files, 3 of them were .msp's. i put all the files in c:\OXPupdates and made a OfficeXP_Slipstreamer.cmd that looks like this. TITLE Office XP Slipstreamer brought to you by www.MSFN.org CLS @echo off ECHO. ECHO Starting the Slipstreaming process of Office XP Updates ECHO. ECHO Slipstreaming Office XP Service Pack 3 ECHO Please wait... msiexec /p MAINSP3ff.msp /a C:\XPCD\$OEM$\$1\install\Applications\OfficeXP\proplus.msi SHORTFILENAMES=TRUE /qb msiexec /p OWC10SP3ff.msp /a C:\XPCD\$OEM$\$1\install\Applications\OfficeXP\proplus.msi SHORTFILENAMES=TRUE /qb msiexec /p VSDEBUGff.msp /a C:\XPCD\$OEM$\$1\Install\Applications\OfficeXp\proplus.msi SHORTFILENAMES=TRUE /qb ECHO. ECHO Slipstreaming Completed! pause EXIT but an error message comes up saying "The installtion package could not be opened. Verify the package exist and you can access it, or contact the application vendor..." i found a thread where someone else had the same problem, but he said it was due to a spelling error.