OK mate, please get this tool and run it (FREE for private use )

http://www.belarc.com/free_download.html

The user accounts are down the left hand side, and are split into local user (your ones) and System.

Help Assistant is like I said: the Microsoft Remote Desktop Help Assistant Account.

Also like I said, SUPPORT_388945a0 is Microsoft's support account, as in 1, Microsoft Way, Redmond, WA. [Better tape up your 3.5" floppy drive or Steve Balmer will sneak out, raid your 'fridge and drink your beer!]

If you have UpdatusUser then you have NVIDIA's automatic updates installed.

ASPNET is the asp.net machine account. It only has "guest" as does the MS (Redmond) support account.

Anything else?.............. you may well have a problem.

Whilst you are using Belarc Advisor, scroll down and check that your Windows updates have installed correctly