Have I been Hacked???????

From: David Carter (dc_post_at_yahoo.co.uk)
Date: 01/23/05 

Date: Sun, 23 Jan 2005 16:04:24 -0000

Hello
I switched my computer on today and found that a new login of "ASP.net" had
been added, it was a full priviledge account.
Can anyone tell me what has happened?
I have no idea what ASP is so I haven't used it.
Thanks
Dave