This is realy a bad answer.
On 5 different PC?s/laptops with different office versions CCleaner deleted wrongly the office extentions in the filetype list. Alle these pc?s does still have this problem today. PC?s where CCleaner is not installed are still working. This was the reason to look for other programs to clean the registry. I trusted CCleaner for years. It was with the CCleaner version around december-januari. This version removed all office document extentions. Today i still have problems on all these pc?s. I always downloaded the version from the internet for every pc separately. During newyear i visited my family and installed CCleaner. A week later i had many phonecalls that the attachments in outlook didn?t work anymore.