There are two commands useful here: ASSOC and FTYPE. In a command line window on my machine, if I type
assoc .sas
it reports
.sas=SAS.Program.701
telling me that the .sas extension is associated with file type SAS.Program.701. Yours probably reports something about ultraedit.
If I then type
ftype SAS.Program.701
it report this command string:
SAS.Program.701="C:\Program Files\SASHome\SASFoundation\9.4\core\sasexe\sasoact.exe" action=Open datatype=SASFile filename="%1" progid=SAS.Application.940
Hopefully you still have an ftype of SAS.Program.701, probably tied to similar command string.
If so you merely need to enter this ASSOC command:
assoc .sas=SAS.Program.701
On my machine, I had to run the command session as an administrator, and I suspect you might have to as well