Windows 10 is working well on most gear. Make sure you check the following before upgrading.
Connect using wired internet if possible; wireless may have issues.
Make sure you have several hours depending on your computer’s speed and size of data.
Many legacy wireless products will have issues — best to get a new adapter if you think your system is older than 4 years.
Office 2003 and older do not work well or not at all. Microsoft’s official word is that Office 2007 and above are confirmed to be compatible, while older versions “are not certified compatible with Windows 10 but might work using compatibility mode.”
Here is a link to our knowledgebase with more details.