The previous suggestions from your posts to read about SET/MERGE by BY as well as taking consideration with using SAS numeric variables for DATE and TIME type references has either been ignored or forgotten.
Individuals on these forums take the time to address the requests for help/guidance, only to find that a subsequent post continues with disregard to others' feedback.
Furthermore, as has been suggested, investing in time for self-checking of your program and the logs will go far to help one absorb useful habits when dealing with SAS program development and debugging.
So, given the latest post and your point about multiple variables representing laptops, as I see it you have two SAS variables, one named LapstopModel and another called LaptopModel -- maybe intentional but who knows. Also, your question is input data related and so you will be best suited to answer it, I believe, unless you are willing to generate SAS log diagnostics using commands, such as:
LIST;
putlog _infile_;
putlog _all_;
Again, to share only a non-working SAS program (as mentioned with the PROC SORT specification error), is not going to get you very far, in my experience. In the future, share all of your SAS code but do so with a captured/pasted SAS log output with it.
Scott Barry
SBBWorks, Inc.