Yes. memoQ uses the spell checker of Microsoft Office for this in the background. If you are using a language version of Microsoft Office 2000 that does not provide built-in support for the language you are translating into, you can simply copy the required files and Office will support that language as well. However, this is not enough when you try to use memoQ spell checking. Because Microsoft Office does not automatically install some elements, you need the original installation CD to proceed.
This is not an issue with Microsoft Office 2003 or newer.