Here's a much quicker way to empty the list. Open QlikView Desktop, click "Help/About QlikView...". On the About QlikView window, notice the QlikView "Q" in the bottom left corner. Right click the Q to open the Settings "Easter Egg" dialog. Scroll down the list until you find "StartPageMruListMaxEntries". Set the value to 0, click "Set" and the list should be empty next time you open it. If you want to start filling it back up, repeat the process and set the value to something greater than zero.
*** DISCLAIMER: Be VERY careful while in the Settings Easter Egg dialog. There are very powerful settings there, which translates to "there are things in there that can REALLY mess up your QlikView installation if you don't know what you're doing!" ***