How many processes should ideally be running?

4wd,

Look this...I only install firefox after first use...

silx2000, I'd believe you can get rid of dozens of services\startup items. But which can go still leaving a fast, fully functional pc? That's up to you, your skills and patience. I can't believe the amount of stuff that gets crammed into new pc's these days.

My personal opinions and basic approach:

Take it over time, be careful, have recent complete backups\images (preferably from a good 3rd party program, creating the usb\cd boot\restore tool) + create fresh windows restore points regularly, should save the day if anything goes wrong). Alternatively, do a clean windows install + only the needed drivers (can be a combination of default windows drivers + some specific stuff from the manufacturer).

I use Ccleaner as the easy way to enable\disable startup items. Process Explorer from Sysinternals is a good tool. Regarding services, set things to manual if in any doubt, choose disabled only when 111% sure about the function of a particular service. Tip: always check Dependencies.

Be careful, don't do more than 1 or 2 changes at a time, spend time reading\googling before acting, it's the alternative to staying up all night trying to undo mistakes lol

WD and Whs,

you are right...

until last year all my new machines I installed a clean windows + essential drivers only, but on last 10 months my job took my time a lot, I'm very tired and for a few moments with this new asus I Thought use factory default windows until I confirm that it was not worth.

My computer routine on last 5 or 7 years was: new clean windows instalation + essential drivers + basic programs + specific programs + personal preferences(shortcuts, email client + wallpapers, etc) after this: CCleaner and defrag and after all: macrium reflect (disk image copy) saved on external drive.

normally once a year or when windows was slow or failing I always replaced instalation for image on backup, and this routine always work fine to me, except when I did hardware upgrade.

well...I just installed clean windows on this morning: 33 services running, now I will install the basic drivers. possibly no more than 50 services will running after basic drivers.