Force Microsoft Word to NEVER auto-capitalize the name of my company

• Under Word Options, select Proofing.
• Select Autocorrect options.
• Enable "Replace text as you type."
• Enter your company name to be replaced with the lower case variant (e.g. Mycompany to mycompany).

Word will now automatically replace the word with the intended phrase. But you will have to type it in caps to start off with for the correction to occur.

Essentially, this swaps the functionality of the Caps key for the first letter of the particular phrase.

Unfortunately, Auto-correct is for correcting spelling, etc, not to ignore basic English syntax.

To get Word to not capitalize your company name at the beginning of sentences, etc., you need to disable that feature for all words.

You can do this in Word's options...

In 2013, its under File :: Options :: Proofing :: Autocorrect Options... and it's an option called "Capitalize first letter of sentences":

Alternatively (perhaps once you're done writing the Word document) you can replace all occurrences, forcing the all-lower case version, by using Word's Search and Replace. This works because when you use replacement text from the clipboard, it doesn't auto-correct it...

• Type "mycompany" someplace in all lowercase.
• Select it and copy it to the clipboard, and then deselect it by clicking elsewhere in the document.
• Hit Ctrl+H to open the Replace dialog.
• In "Find what:", enter Mycompany (casing doesn't matter here).
• Click "More >>" to expand the advanced options.
• Click the "Replaced what:" box to activate/focus it.
• Click "Special" button, and choose "Clipboard contents" (this will put ^c in the Replace box).
• Click "Replace All".

Options -> Proofing -> Auto-Correct Option then un-check "Capitalize first letters of sentences.

Unfortunately this applies to all words that start sentences, but it is the only way I know of preventing this.

This is because in this case it is not being capitalised because it is "my" but because it starts a sentence - and Word believes that sentences either start with a capital letter or they do not. It does not allow finer grained control than this AFAIK.