What's a .xll file extension
File Details: .xll files are a fairly common type of plugin file that we are asked often about. This file is a Excel Add-In File and like other plugin files require special software. Need some information about .xll files? Ask WhatsAFile.com and get an answer in 12hrs or less for free.
Think you have a registry error? 98% of computers do!
Run A Scan for .xll related registry errors.