permissions/users

i have a couple issues but i'll post this one first..in an attempt to change permissions on files i migrated to my new w-7 pc i found this, see screen shot...who/why/when and WTF? are these users on my new pc?

please advise..anyone
thanks

For one, the MAIN user assigned all rights on the W7 machine is not YOU, it is an administrator account with no logon privileges (by default). There are guest accounts, accounts for Services, accounts to remotely assist with your computer (or even allow you to run it from work). Etc. Numerous accounts but most don't have login access by default. Follow the Microsoft Link for a detailed description.

Microsoft Link