Windows' SAS Installations are not a lot like Linux, if you will just remove the SASHome and SASConfig, it will still not work, you've to remove Registry entries for SAS From following registry paths also (I'll recommend taking full registry backup before you perform this step):
1. HKEY_CLASSES_ROOT (there will be many entries for SAS In this path)
2. HKEY_CURRENT_USER\Software
3. HKEY_LOCAL_MACHINE\Software
After the above steps, remove all SAS related folders and subfolders from %TEMP% and %APPDATA% directories,
Now reboot the machine, and than start the installation again from the scratch.
Probably you can start the installation again without any errors.
NOTE: I'm considering that your machine doesn't have any SAS Services installed, if any services are installed, you have to remove services by "sc delete <service_name>" command.