Installer gets stuck with a grayed out forward button

I recently encountered the same problem installing Ubuntu on a friend’s computer. It seems that Ubiquity (the Ubuntu installer) for 10.10 is not very informative when things go wrong. Does your username contain uppercase letters? Try making sure all letters in your username are lower case.

For more details, see: How should I file a bug about Ubiquity?

Corresponding Bug Reports:

• Username starting with upper letter marked as OK during install and the refused
• Ubiquity should give visual feedback that username cannot contains capital letter(s)

Each line in the installer should have a green check-mark next to it. For example, if you've not entered a password or mistyped the password, the "Forward" button will remain greyed out.

We used to get this question a lot, at https://answers.launchpad.net/ubuntu.

Depending on what version of Ubuntu you are installing, this may be happening because you've entered an invalid username.

• On Ubuntu releases prior to 11.04, the installer doesn't show any message to inform users that they've chosen invalid usernames. This produced considerable confusion, since many users didn't know why they couldn't continue on with the installation. That seems to be what's going on here.

  This was reported as bug 549195 and fixed for Ubuntu 11.04 and later.

If you choose a username consisting only of lower-case letters (and, if you want, also numbers, but not as the first character), and no punctuation or spaces, that should enable you to proceed forward with the installation.

• Some punctuation-like characters are allowed, but not most. Here are the details, from a post on Launchpad Answers by Colin Watson (#4 here):

  Make sure that your username begins with a lower-case letter, and contains only lower-case letters, digits, hyphens (-) or underscores (_). Upper-case letters and spaces, in particular, are not allowed. (Of course, the full name can be whatever you like.)

If you still cannot click Continue, then you should MD5 test the installation .iso image you used to make the live CD/DVD or USB flash drive. If that doesn't check out, you'll have to download a new .iso file and start over. If that does check out, then check the installation media (CD/DVD or USB flash drive) for defects.

If your username starts with a letter and doesn't contain any disallowed characters, and the .iso image and the installation media you created from it are good, and this problem still occurs (which is unlikely), then you should still be able to install with the text-based alternate CD.