Hi Jbush24,
If there is a failure with a particular installation package there is no need to remove WebPi to start over again. What webpi does is advertises the various programs you can choose to install and then chains the installations of these programs. If you do still want to remove it you can do so from Add Remove Programs in Control Panel. This however does not remove programs you installed as they would be installed individually.
So in your case if its the SQL Server Express installation that failed you can look here for information on the installation logs as to why this failed.
How to: View SQL Server Setup Log Files
http://msdn.microsoft.com/en-us/library/ms143702.aspx
Troubleshooting an Installation of SQL Server
http://msdn.microsoft.com/en-us/library/ms143698.aspx
Please feel free to post back with any questions with the logs or would like us to review the logs please zip up the logs from the following location and send to webpi@microsoft.com .
<drive>:\Program Files\Microsoft SQL Server\100\Setup Bootstrap\LOG\.
As to why you dont see Visual Studio, this has a dependency on the SQL installation so if that failed then the Visual Studio Installation would not complete.
I hope that helps
Richard