一張圖以蔽之：
2007/04/30 補：
後來實測MS的Edit.com版本2.0.026，壓縮後無法執行=.=，
會顯示error 255: Unable to load string resources!
另外MS的Command.com壓縮後，開機後會顯示找不到Command -.-。
所以
MS的Edit.com和Command.com用UPX壓縮後無法執行，
所以這2個檔案不壓縮。
2007/05/20 修正：
Append.exe 12,470 -> 7,773
Attrib.com 5,044 Not Compressible Exception
AwdFlash.exe 44,201 -> 23,458 (8.33A)
Chkdsk.exe 27,984 -> 10,052 Not Use 無法使用
CMOS.com 3,317 -> 2,338
Command.com 93,040 -> 33,932 Not Use 無法使用(The following file is missing or corrupted:COMMAND.COM)
Debug.exe 20,490 -> 13,265 Not Use 無法使用
Deltree.com 4,210 -> 3,068
Diskcopy.exe 44,414 -> 24,405
DOSLFN.com 11,524 Already Packed Exception
Edit11.com 413 Can't Pack Exception: file is too small(Need QBasic)
Edit.com 62,542 -> 40,741 Not Use 無法使用(ERROR 255: Unable to load string resources!)
Emm386.exe 12,727 Not Compressible Exception
Extract.exe 53,767 Can't Pack Exception: can't pack new-exe
Format.exe 32,489 Already Packed Exception
Himem.exe 7,891 Not Compressible Exception
Label.exe 4,129 Already Packed Exception
Mem622.exe 32,502 -> 18,433 版本限制
Mem.exe 7,587 Already Packed Exception
Mema.exe 8,089 Already Packed Exception
Memtest.exe 83,156 -> 32,922
More.exe 4,601 Already Packed Exception
Mouse.exe 5,012 Already Packed Exception
MSD.exe 165,864 Can't Pack Exception: can't pack new-exe
NTFSDOS.exe 53,243 -> 26,507
Pkunzjr.com 2,916 Not Compressible Exception
QBasic.exe 194,309 Can't Pack Exception: can't pack new-exe
ScanD98.exe 144,210 Can't Pack Exception: can't pack new-exe
ScanDisk.exe 245,924 -> 107,875 Not Use 無法使用(Localized text missing or corrupt)
Smartdrv.exe 45,379 Can't Pack Exception: unexpected value in header
SPFDisk.exe 134,496 -> 68,978
Sys98.com 19,159 -> 8,800 Not Use 無法使用
Sys.com 9,260 Already Packed Exception
SysME.com 22,119 -> 9,068 Not Use 無法使用(Only to C:)
Tree.com 9,893 Already Packed Exception
WipeCMOS.com 930 Can't Pack Exception: file is too small
Xcopy.exe 16,442 Already Packed Exception
YMark2K.exe 10,877 Not Compressible Exception
