Hetti, I presume its not a wireless networking card which has been moved from your main to the 2nd PC?
Which would then be an industry standard wired Ethernet card, compatible with all routers including D-Link.
If you are running Windows XP, it will have its own generic drivers for any wired ethernet card, and you will get internet access on startup.
However, the specific driver for your specific card would work best, which is presumably what he installed.
If the fella concerned had completed the job correctly, you would not have this problem. It might well be there is some other issue with your 2nd PC which needs to be sorted out 1st, but which he did not bother to check.