You're just more diligent than I am. If I can't get it installed, I toss my hands up & move on. Since I've started working exclusively on virtuals when I'm doing a beta, I've had fewer install problems. It comes from not having to worry about uninstalling all the previous betas.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning