I write about a specialist subject for my living and over the years I have built up a custom.dic of specialist terms that now totals almost 60,000 words (it also includes non-specialist words, of course). I was using Word 2003 until I recently upgraded my PC and, with it, I upgraded to Office 2010, thus I now use Word 2010. In Word 2003 I called this specialist dictionary custom2.dic and it seemed simple enough to place a copy into the correct directory, go to File, Options, Proofing and click on Custom Dictionaries to make custom2.dic my default. However, as soon as I use Spellcheck, this file is reduced from 1.08MB to 170KB, and the words reduced to just 9,000-odd. Any ideas why this happens and, more importantly, any suggestions, please, how I can retain all 60,000 words?

I’ve worked it out! I copied the list of words from Custom.dic to Excel and sorted to find lots of words duplicated 5, 6, 7, 8 times or more, so I filtered to unique records only, and ended up with 9,000-odd words! Silly me, Word 2010 was only tidying up my old, heavily duplicated dictionary. Sorry to have bothered you guys, who kindly give time to help others.

Thank you for posting the update.