If it has an operating system why do you want to connect it to yours. Just boot it up and install a free anti-virus and some anti spyware/malware programs.....clean it up and give it to them.

If the computer is slow then download the programs to burn to disc and install that way.

I use these.....all free...and highly recommended:
anti virus
|MG| AntiVir Personal Edition 7 7.06.00.270
spyware removal
|MG| Ad-Aware 2007 7.0.2.6 (125\08 Update)
|MG| SpywareBlaster 3.5.1
|MG| ATF Cleaner 3.0.0.2

|MG| CCleaner Slim (No Toolbar) 2.04.543

|MG| WinPatrol 14.0.2007.1

That is what I use and have been for years.