I guess you mean system.ini. Add this to your msbatch.inf: [UPD.Sys.systemini] %10%\system.ini, 386Enh, , "32BitDiskAccess=on" %10%\system.ini, 386Enh, , "32BitFileAccess=on" %10%\system.ini, 386Enh, , "PagingDrive=C:" %10%\system.ini, 386Enh, , "PagingFile=C:\PAGEFILE.SYS" %10%\system.ini, 386Enh, , "MinPagingFileSize=200704" %10%\system.ini, 386Enh, , "MaxPagingFileSize=200704" %10%\system.ini, 386Enh, , "WindowUpdateTime=1" %10%\system.ini, 386Enh, , "LocalLoadHigh=1" %10%\system.ini, 386Enh, , "VGA MonoText=Off" %10%\system.ini, 386Enh, , "Text=Off" %10%\system.ini, 386Enh, , "ConservativeSwapfileUsage=1" %10%\system.ini, vcache, , "MaxFileCache=32768" %10%\system.ini, vcache, , "ChunkSize=2048" [Install] UpdateInis=UPD.Sys.systemini NEVER set a maximum for the swap file unless you REALLY need to do so. NEVER use ConservativeSwapfileUsage=1 unless you REALLY need to do so. (Why should one downgrade to the legacy W95 mode of swap handling?) Naming the swap file Pagefile.sys (only) makes sense when the swap file is shared with another OS which uses a swap file with that name. The value for MaxFileCache might be way too small for many machines - individual adjustment is required. The ChunkSize setting is questionable.