Windows 7: Built-in OEM Administrator Account Issues

When I suggest the possibliity that the "User must enter a user name and password to use this computer" being unchecked might cause a problem, let me clarify. Originally, there was no password for the built-in Administrator account. Yesterday, the system forced me to change the password, which seemingly spawned (or enabled) my user name account (as opposed to simply changing the password for the built in Administrator account). Now, if I enter no password, I am auto-logged on to the Administrator account which is not want I want (all my documents etc. have been magically moved to my user account) but might be happening because of some kind of autologin set up from before. If I set a password for the built-in Administrator account, it gives me an error message (wrong username or password) perhaps generated because the system is trying to auto-login to the administrator account with no password (as specified by some kind of auto-login registry setting). There are some details here which may be of interest:
Windows 7 Auto Logon Enable | Regedit AutoAdminLogon AutoLogonCount

which begs the question whether I can simply make some registry tweaks to instead login my named user account with a default password as described in the above link? That would be the perfect solution, although I would like to make sure that it's safe first, I don't want to be completely locked out of my system obviously...

Here's a screenshot

OK, some good news, basically I did the opposite of what was described here:
Tip: Auto-Login Your Windows 7 User Account | Cool Stuff | Channel 9

I CHECKED the box that says "Users must enter a username and password to use this computer". Now I can have the built-in Administrator account enabled (so no more messages about the account being disabled) and I am not automatically logged into that account.

Now, if I could only figure out why my computer is pausing for an additional 15 seconds or so (compared to a few days ago) while the message "Windows is starting up" is displayed... On a lightning fast, top of the line computer is it normal to see that message for 25 - 30 seconds? Seems to me it used to be more like 10 - 15s before that I would see that message on the screen.

For some that is a normal thing.

Solving slow startup problems is normally simple.

Attach the startup.txt file as described here:

list of STARTUP PROGRAMS
CCleaner | Tools icon | Startup button |
click on Save to text file button (bottom right side)

Using the PAPER CLIP icon (top panel of a Message Reply),
attach the startup.txt file generated by CCleaner
CCleaner - Optimization and Cleaning - Free Download

Just to specify, I am refering to pre-login startup. I don't think any startup programs have a chance to load at that point, I'm thinking it might be more a driver issue? However, I think it might be proper to start a new thread?

Sounds goodl

As previous posts have said, you need to turn off Autologon feature.

If you are using Win 7 Professional you can use lusrmgr.exe to turn off autologon, for Home users, there is a seperate tool called Netplwiz.exe which can be used to turn off autologon.