You might want to do a factory reset especially if this was given to you with Bit Torrent programs on it. Just to cover your OWN ass. Also, you'll want to backup any of YOUR information and do the complete system reset where it erases the hard drive and repalces the core system files. You will then remake your profile, reload your data and should be smooth sailing.
If you wish to investigate into the TAAA Account further then start by pressing "Start" and in the search field type "User Accounts" then in the user accounts window click "Manage User Accounts" look for the user in that list and delete it if its there. If not you can continue looking for it by Clicking in the "Advanced" tab and then clicking the Advanced button A new window pops up and click the Users folder on the left most column of this window. If you see the user name appear in the middle column highlight it, right click and delete it
If its not there click the "Groups" folder on the left-most column. Check each of the "Administrative" style groups by double clicking the entry in the middle column and again search for that user name, you may not be able to delete it from here we're just checking for any entries that correspond with this.
One last thing if you still have not found the user is to click the start button again, highlight "Computer" and right click it. Then choose properties. From the properties window pop-up choose "Advanced System Settings" and then when the System Properties window pops-up look under the "User Profiles" heading for the "Settings" button and click it. Here you should see a list of the accounts locally on the computer and you can delete it from the menu, its a straight forward process.
If you still cannot find and erase the account name you are looking for I highly, highly reccomend a factory reset any way possible whether it be from a recovery partition, a disc that came with the computer or calling the OEM that manufacturered the computer and ordering a rescue disc.