When you go to install a version of the Cloud Retailer POS, there are times where windows update or other software updates are pending a reboot of your computer. In this situations, Cloud Retailer POS will fail to install. You'll see the installer nearly finish and then at the end roll back.
Here are a few things to try:
1) Make sure any pending windows updates have finished
2) Make sure you're logged in as the user that originally installed Cloud Retailer POS. Typically this is an admin type user and the current user may not have permissions to access the local database for security reasons.
You can also find verbose logging as it relates to installers here:
Look for a file with a name like Cloud_Retailer_POS_
Errors can include ox84be0bc2 (SQL cannot install due to pending Windows updates - typically)
This security id may not be assigned as the owner of this object (limited user is currently logged in)