By default, Word acts as your watchful grammar guardian. As you type, it underlines potentially misspelled words in a vibrant red squiggle. This real-time feedback helps you catch errors early on, maintaining the flow of your writing. Unfortunately, Microsoft Word doesn't have built-in Khmer spell checking.

Therefore ភាសាខ្មែរ-KhmerLang's team recently published Microsoft Word Addin which  it can be a helpful tool for checking Khmer text.

ពិនិត្យអក្ខរាវិរុទ្ធភាសាខ្មែរ - Khmerlang Spell Checking

Addin doc

You can install "ពិនិត្យអក្ខរាវិរុទ្ធភាសាខ្មែរ - Khmerlang Spell Checking" add-ins for Microsoft Word: