Windows File Extensions – Is There a Length Limit?

Try the following:

• Open the registry editor (Start ⇨ regedit)
• Navigate to the key HKEY_CLASSES_ROOT\.TXT
• Select File ⇨ Export and save it to a .reg file
• Open the .reg file in a text-editor (e.g., Notepad)
• Perform a search-and-replace to replace all instances of .TXT to .txt
• Save
• In regedit, delete the key HKEY_CLASSES_ROOT\.TXT
• Double-click the .reg file and select [Yes] to import/merge it
• Reboot

Open the Registry Editor, navigate to HKCR (although HKCU\Software\Classes would be a better location, but most are lazy). For every file type, create a zero-length string value named AlwaysShowExt.

For example, if you have .txt:

1. Navigate to the subkey for the extension – HKCR\.txt – and note the data stored in the "(Default)" value – it usually says txtfile.

2. Navigate to the file type subkey HKCR\txtfile, right-click the value list, choose New → String value, and name the new value AlwaysShowExt.

Not all extensions have separate subkeys for file types – sometimes all information is kept directly under HKCR\.myext. In such cases, AlwaysShowExt goes directly to the extension subkey as well.

It is very likely that there are dedicated programs for editing file types, possibly with support for AlwaysShowExt and other flags. I don't know any to recommend, though.