Hi, could you take a few pictures of the inside of your new computer? I have not heard of hardware you can add to a computer to give it a virus or malware (other then a flashdrive, disk, or extra harddrive).
If you have any doubts,
1. Download Hijackthis
http://download.cnet.com/Trend-Micro-HijackThis/3000-80...;1
A. After you have downloaded it, run it and save the report (DO NOT DO ANYTHING ELSE, do not mess with anything on it)
B. Go to this website
http://hijackthis.de/index.php?langselect=english and post your results, read through it and see if it has picked up anything.
2. Download Malwarebytes
http://download.cnet.com/Malwarebytes-Anti-Malware/3000...;1 and run it
3. Download Hitman Pro 3.5
http://www.surfright.nl/en/downloads/ run it and fix anything it find.
After you have done all that you can rest assured that your computer is clean.