How to change entire system permission to my account?

Why not d a Clean install on the newer computer and then copy over your files.

Probably simpler and less time consuming.

You should have used Setup Assistant, not Migration Assistant, to transfer your data. I suggest you start over and do that now.

OSX Tips: Setting-up a new Mac from an old one, its backups, or a PC Using Setup Assistant on Lion

Repairing the permissions of a home folder in Lion is a complicated procedure. I don’t know of a simpler one that always works.

Launch the Terminal application by entering the first few letters of its name into a Spotlight search. Drag or copy – do not type – the following line into the window, then press return:

chmod -R -N ~

If you get an error message about permissions, enter this:

sudo !!

You'll be prompted for your login password, which won't be displayed when you type it. You may get a one-time warning not to screw up.

Next, boot from your recovery partition by holding down the key combination command-R at startup. Release the keys when you see a gray screen with a spinning dial.

When the recovery desktop appears, select Utilities ▹ Terminal from the menu bar.

In the Terminal window, enter “resetpassword” (without the quotes) and press return. A Reset Password window opens.

Select your boot volume if not already selected.

Select your username from the menu labeled Select the user account if not already selected.

Under Reset Home Directory Permissions and ACLs, click the Reset button.

Select  ▹ Restart from the menu bar.

OS X Lion: About Lion Recovery

Did you get all your permissions taken care of? I have THE EXACT same issue. Bought the Mac second hand. Set up new user, blah blah blah. I would love to know if this worked. If not, what have you done to fix your "permissions" ??