Internet Explorer 6 contains a hard-coded list of unsafe files in the shdocvw.dll file. IE 6 uses the unsafe-file list to prevent you from accidentally opening a file type that might cause problems on your computer.

The complete list of unsafe extensions is:

• .ad
• .adp
• .asp
• .bas
• .bat
• .chm
• .cmd
• .com
• .cpl
• .crt
• .exe
• .hlp
• .hta
• .inf
• .ins
• .isp
• .js
• .jse
• .lnk
• .mdb
• .mde
• .msc
• .msi
• .msp
• .mst
• .pcd
• .pif
• .reg
• .scr
• .sct
• .shb
• .shs
• .url
• .vb
• .vbe
• .vbs
• .vsd
• .vss
• .vst
• .vsw
• .ws
• .wsc
• .wsf
• .wsh

You can add file extensions to the unsafe-file list:

• Navigate to:

  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\UnsafeFiles\Include
  You will have to create the key if it does not exist. It won't.

• From the Edit menu, select New, Key
• Enter the extension you want to add
  for example if .wsh were not in the default list, you could add it:
  .wsh

You can make exceptions to the unsafe-file list:

• Navigate to:

  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\UnsafeFiles\Exclude
  You will have to create the key if it does not exist. It won't.

• From the Edit menu, select New, Key
• Enter the extension you want to exclude
  for example to exclude .exe from the default list, add it:
  .exe

Messed up or want to get back to defaults, just delete the keys you added. In most cases delete the UnsafeFiles key.