La mejor manera es intentar usar el menú contextual Open With...
para establecer que Explorer sea el manejador de archivos por defecto.
Sin embargo, si eso no funciona puede probar lo siguiente para forzar al Explorer a manejar el archivo ZIP. (http://www.vistaheads.com/forums/microsoft-public-windows-vista-general/270951-vista-how-do-you-restore-default-behaviour-zip-other-file-types.html)
Haga un archivo .reg con lo siguiente:
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\.zip]
"PerceivedType"="compressed"
"Content Type"="application/x-zip-compressed"
@="CompressedFolder"
[HKEY_CLASSES_ROOT\.zip\CompressedFolder]
[-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.zip\UserChoice]
[HKEY_CLASSES_ROOT\.zip\CompressedFolder\ShellNew]
"Data"=hex:50,4b,05,06,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
"ItemName"=hex(2):40,00,25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,\
6f,00,74,00,25,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,\
00,7a,00,69,00,70,00,66,00,6c,00,64,00,72,00,2e,00,64,00,6c,00,6c,00,2c,00,\
2d,00,31,00,30,00,31,00,39,00,34,00,00,00
[HKEY_CLASSES_ROOT\.zip\OpenWithProgids]
"CompressedFolder"=""
[HKEY_CLASSES_ROOT\.zip\PersistentHandler]
@="{098f2470-bae0-11cd-b579-08002b30bfeb}"
[HKEY_CLASSES_ROOT\CompressedFolder]
@="Compressed (zipped) Folder"
"FriendlyTypeName"=hex(2):40,00,25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,\
00,6f,00,6f,00,74,00,25,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,\
32,00,5c,00,7a,00,69,00,70,00,66,00,6c,00,64,00,72,00,2e,00,64,00,6c,00,6c,\
00,2c,00,2d,00,31,00,30,00,31,00,39,00,35,00,00,00
[HKEY_CLASSES_ROOT\CompressedFolder\CLSID]
@="{E88DCCE0-B7B3-11d1-A9F0-00AA0060FA31}"
[HKEY_CLASSES_ROOT\CompressedFolder\DefaultIcon]
@=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\
00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,7a,00,69,00,\
70,00,66,00,6c,00,64,00,72,00,2e,00,64,00,6c,00,6c,00,00,00
[HKEY_CLASSES_ROOT\CompressedFolder\shell]
@="none"
[HKEY_CLASSES_ROOT\CompressedFolder\shell\find]
"SuppressionPolicy"=dword:00000080
[HKEY_CLASSES_ROOT\CompressedFolder\shell\find\command]
@=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\
00,5c,00,45,00,78,00,70,00,6c,00,6f,00,72,00,65,00,72,00,2e,00,65,00,78,00,\
65,00,00,00
[HKEY_CLASSES_ROOT\CompressedFolder\shell\find\ddeexec]
@="[FindFolder(\"%l\", %I)]"
[HKEY_CLASSES_ROOT\CompressedFolder\shell\find\ddeexec\application]
@="Folders"
[HKEY_CLASSES_ROOT\CompressedFolder\shell\find\ddeexec\topic]
@="AppProperties"
[HKEY_CLASSES_ROOT\CompressedFolder\shell\Open]
[HKEY_CLASSES_ROOT\CompressedFolder\shell\Open\Command]
@=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\
00,5c,00,45,00,78,00,70,00,6c,00,6f,00,72,00,65,00,72,00,2e,00,65,00,78,00,\
65,00,20,00,2f,00,69,00,64,00,6c,00,69,00,73,00,74,00,2c,00,25,00,49,00,2c,\
00,25,00,4c,00,00,00
"DelegateExecute"="{11dbb47c-a525-400b-9e80-a54615a090c0}"
[HKEY_CLASSES_ROOT\CompressedFolder\ShellEx]
[HKEY_CLASSES_ROOT\CompressedFolder\ShellEx\ContextMenuHandlers]
[HKEY_CLASSES_ROOT\CompressedFolder\ShellEx\ContextMenuHandlers\{b8cdcb65-b1bf-4b42-9428-1dfdb7ee92af}]
@="Compressed (zipped) Folder Menu"
[HKEY_CLASSES_ROOT\CompressedFolder\ShellEx\DropHandler]
@="{ed9d80b9-d157-457b-9192-0e7280313bf0}"
[HKEY_CLASSES_ROOT\CompressedFolder\ShellEx\StorageHandler]
@="{E88DCCE0-B7B3-11d1-A9F0-00AA0060FA31}"
Luego, en un prompt de comando de administrador escriba:
regsvr32 zipfldr.dll
Otra sugerencia que he visto es simplemente ir al editor de Programas predeterminados en el Panel de control y eliminar la asociación que tienes actualmente. Sin embargo, esto era para XP y no estoy seguro de que funcione para Vista. Sin embargo, es posible que desee probar esto antes de jugar alrededor del registro.