Starting this weekend, Wal-Mart plans to change where you’ll shop for your next computer, while possibly providing a needed salesboost to OEMs whose profits have fallen due to weaker sales. For most companies, such statements would smack of hubris, but Wal-Mart’s size and recession-resistant business model lend credence to the idea that the store could spark an uptick in consumer demand. As the first step in that process, beginning Sunday, Wal-Mart will offer a Compaq Presario notebook for $298.Said noteboook