Generally blue screens (BSOD) is caused by a hardware issue such as a graphics card. Set your graphics card settings back to default to see if this helps.
* Also, After opening LW wait 10 to 20 mins or longer before using. Let it settle down 1st.
* Go to LW's prefs>Speed & tick disable Ultrapeer Cap. & press apply button.
* Set both uplds & downlds to autoclear.
* Don't use the Resume button on all incomplete files. This can have side-fx such as affect LW's connection quality. May queue your files for much much longer. This will also stress LW & your comp. If you use Resume/Find sources then just apply it to a couple or so at one time.
* Tip: Purge the Downloads Queue!

Don't forget to configure your Norton Firewall; Configuring Norton Internet Security & disable your XP firewall as they may interfere with each other! 2 active firewalls issue