In HKEY_USERS\S-1-5-21-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxx-xxxx\Software\Microsof\TATrial and HKEY_LOCAL_MACHINE\SOFTWARE\Microsof\TATrial there are entries Default (no value set) InstallDate (733998) and UseCount (3). I do not have an antivirus on this machine because it's slow and am wondering if there is reason to be concerned?
If I were to take a guess, I'd say that it had to do with some sort of software (possibly from Microsoft, but just as likely not) that you had installed a trial version of. The registry contents don't appear to be malicious; an install date and usage count isn't particularly insidious. If you're to be concerned, I'd think it would be for some other reason than this.
You're bound to find LOTS of registry entries you can't immediately place off-hand. That's sort of the nature of the registry.
I would guess it could be a malware. I have very little to go off of, but I found a spanish forum (google translated below):
@ abinadar Hace 2 años
This person was noting the registry key called TATRIAL210 inside of "microsof" registry folder. A misspelling would more than likely be some form of malware.
EDIT: http://forum.sysinternals.com/microsof-reg-entrys-3_topic4953.html Possibly not virus. Are you using software called "Text aloud?"