That depends. If you are only going to use your laptop for mundane things like surfing the Internet, sending and receiving email, creating the occasional document, ripping/burning music from your store-bought CDs, and so one, a laptop from Wal-Mart will perform well enough.
For the record, Wal-Mart doesn't manufacture laptop computers. They merely sell computers that have had the names of companies (such as Acer, HP, eMachines, and Compaq) slapped on them.
The laptop I'm using to answer this question is an Acer Aspire 5515, which I bought from Wal-Mart on 2009-05-06 (YYYY-MM-DD) at 00:23:10 (Eastern Time).
So far, I don't have any problems with it. I didn't buy the optional extended warranty because electronic things don't break down in my presence.
It only cost $348.00 plus tax ($368.88) and I'll be thrilled if it lasts two years. It ran Windows Vista Home Basic at an acceptable speed until I jettisoned Windows Vista from the hard drive and installed PCLinuxOS. It runs PCLinuxOS even faster than it ran Windows Vista.