quick (2 hour) maintenance on a laptop..

my friend wants to drop off his laptop for a couple of hours this evening before picking it up and tomorrow early morning he takes it to his business meeting across the country. his concern is his poor performing laptop will show up in the meetings..

what are the basic maintenance you can and should do in a couple of hours, in a poorly maintained system.
(this user has not done any backups and has installed lot of older software's that are not being used now etc). I did ask and he is running a free AV.

after he comes back to town in a few days, i will suggest to him bigger tasks like backups etc. can you also list what will be the other BIGger tasks that he should focus when he has the time.