See 11-12MB then 8MB use after disable for Norton. Only 11-12% the most for memory use, could be browser is open or something else, pretty good see. Look at performance, Details tab, all processes running and then can always disable the startup items in the Startup tab, all matters if need it running or not, mostly can be done within the software itself rather then doing it here unless there is no way to. Forget amount of RAM you had, but you seem fine. Always matters what is processing at time of capture too.
Microsoft ones should not be disabled, those are Microsoft ones you are showing, usually towards bottom of the list. Take a look at startup tab, for items start when PC does, Details tab will show you all that is running now. Don't concern yourself too much, not like PC running slow and have 16GB RAM, plenty.
Want good free program to look startup items over and think i suggested it CCleaner - Download
I think I've been lucky to never have any major issues with any of the operating systems I've ever used. I also try to steer clear of missing with the registry. I don't like to apply any kind of reg hacks, if I can live without it, I don't see the point of hacking the registry.
I also only use Ccleaner's registry cleaner after uninstalling, so I'll know what to expect.
Once a month open case up and used canned air, get that dust and dirt out of there as they can damage hardware. Sometimes have to remove certain hardware to do a good job. I have had issues over time, but used computers for many years, to me it always was a learning process on each as time went on. Try Revo Uninstaller it's one of the best, then you can use Ccleaner to clean up rest, but always use Ccleaners reg. backup and make restore points.
I purchased a Metro Vacuum ED500 for about $60 on Amazon and it's paid for itself many time over already. I highly recommend this product, it's well worth the $60. I use it to clean my machine every 2 or 3 months.
I use to buy those cans of air and it can get really expensive over time. I also need to remove certain hardware for my case in order to thoroughly clean all the dust out. It seems that here is AZ, the dust accumulates much quicker then it did back east.
I even take the cover off my power supply once a year and blow that out too.
I've used Revo before and it's a great piece of software.