My computer suddenly has a new user (limited use) machineA .net - is this something to worry about?

I have recently installed BT Yahoo! Total Broadband, Norton Security software and Java updates.

My computer suddenly has a new user (limited use) machineA .net - is this something to worry about?free antivirus download

If you loaded a new OS, like BT Yahoo.....it automatically opened a limited new account for you....simply go into the Admin settings and delete it.....but DO delete it.

My computer suddenly has a new user (limited use) machineA .net - is this something to worry about?internet security

hmmmm if you did not make this user than it is worrying i dont think any of those programs would make a new user try deleting the user and if one of these programs no longer work use system restore to restore back(make a restore point first)
Go to Trend Secure and download HiJackthis at below link

Examine the results at one of the many websites Bleeping Computer or Cybercops check through results carefully for any 'bad' entries before fixing them.

http://www.trendsecure.com/portal/en-US/...
The same thing happened to me, and my entire desktop, start menu, My Docs was all cleaned out. I ended up reinstalling windows and it was fine.
why do want anything of norton it's that what as corrupted your system. Was it ok before you put it on.
I'm not sure. I googled and couldn't find a definitive answer.