Is it possible to modify a registry entry via a .bat/.cmd script?

@Franci Penov - modify is possible in the sense of overwrite with /f, eg

reg add "HKCU\Software\etc\etc" /f /v "value" /t REG_SZ /d "Yes"

You can use the REG command. From http://www.ss64.com/nt/reg.html:

Syntax:   REG QUERY [ROOT\]RegKey /v ValueName [/s]   REG QUERY [ROOT\]RegKey /ve  --This returns the (default) value   REG ADD [ROOT\]RegKey /v ValueName [/t DataType] [/S Separator] [/d Data] [/f]   REG ADD [ROOT\]RegKey /ve [/d Data] [/f]  -- Set the (default) value   REG DELETE [ROOT\]RegKey /v ValueName [/f]   REG DELETE [ROOT\]RegKey /ve [/f]  -- Remove the (default) value   REG DELETE [ROOT\]RegKey /va [/f]  -- Delete all values under this key   REG COPY  [\\SourceMachine\][ROOT\]RegKey [\\DestMachine\][ROOT\]RegKey   REG EXPORT [ROOT\]RegKey FileName.reg   REG IMPORT FileName.reg   REG SAVE [ROOT\]RegKey FileName.hiv   REG RESTORE \\MachineName\[ROOT]\KeyName FileName.hiv   REG LOAD FileName KeyName   REG UNLOAD KeyName   REG COMPARE [ROOT\]RegKey [ROOT\]RegKey [/v ValueName] [Output] [/s]   REG COMPARE [ROOT\]RegKey [ROOT\]RegKey [/ve] [Output] [/s]Key:   ROOT :         HKLM = HKey_Local_machine (default)         HKCU = HKey_current_user         HKU  = HKey_users         HKCR = HKey_classes_root   ValueName : The value, under the selected RegKey, to edit.               (default is all keys and values)   /d Data   : The actual data to store as a "String", integer etc   /f        : Force an update without prompting "Value exists, overwrite Y/N"   \\Machine : Name of remote machine - omitting defaults to current machine.                Only HKLM and HKU are available on remote machines.   FileName  : The filename to save or restore a registry hive.   KeyName   : A key name to load a hive file into. (Creating a new key)   /S        : Query all subkeys and values.   /S Separator : Character to use as the separator in REG_MULTI_SZ values                  the default is "\0"    /t DataType  : REG_SZ (default) | REG_DWORD | REG_EXPAND_SZ | REG_MULTI_SZ   Output    : /od (only differences) /os (only matches) /oa (all) /on (no output)

Yes, you can script using the reg command.Example:

reg add HKCU\Software\SomeProductreg add HKCU\Software\SomeProduct /v Version /t REG_SZ /d v2.4.6

This would create key HKEY_CURRENT_USER\Software\SomeProduct, and add a String value "v2.4.6" named "Version" to that key.

reg /? has the details.