I installed Ubuntu but I can't access it.

I installed Ubuntu to my Dell 15R Inspriron. When I restart it, I can choose between Windows and Ubuntu.

The first choice from there is Ubuntu, the second is Ubuntu recovery mode, and the next two are something about Windows.

The first choice gets me to login to Ubuntu with a username and password, then just gives me a purple screen. It goes nowhere from there. The third and fourth option take me back to choose my OS (Windows or Ubuntu).

I downloaded Ubuntu and I want to use it but I can't because it won't open no matter what!

When I first installed it, I installed it "alongside Windows".

The other option it gave me, which told me to reboot while the CD was in the computer never worked because it would just reboot back to Windows.

Any help will be greatly appreciated!