I have seen a number of questions on this site regarding slow wireless problems. Many of them discuss problems relative to specific wireless cards.
Could someone please explain to me how to find out what wireless card I have in order to begin to diagnose the problem?
What other information might I need and how do I find that?
Usually if you go to your computer manufacturer's web site and search for the model number that you have, there's a page of hardware specifications that would have this info.
For example, if you scroll down to Wireless, this page says that a Dell Inspiron 14R has an Intel® Centrino® Wireless 2230, 2x2 bgn + Bluetooth:
http://www.dell.com/us/p/inspiron-14r-5421/pd?oc=fncwy78s&model_id=inspiron-14r-5421#TechSpec
If that doesn't work, it also might be in the BIOS.