Answer 2
Pretty much everything I can think you'd need on your system should be installed by default or installed as part of the Visual Studio package.
First, are you an administrator? When you run the install does it ask you if you want to grant access or does it just fail? You must be an administrator level user or run the install as a user who is an administrator.
If you're getting past that, check likely things like disk space is insufficient.
Try installing fewer options and see if you can get the base system installed. You can install the other features later if you need them.
If you have a conflicting versions of SQL Server Express installed you might get a conflict. If you've already tried installing other software that might be part of the package you could try uninstalling them before re-running the setup.
If you can post any error messages shown on the screen or from the event log, that would help us figure out the problem you're having and how to fix it.