Based upon the type of issues you are having it sounds like your installation medium was corrupt, which resulting in incomplete packages.

What did you use to install Ubuntu, a home written disk, a flash driver, a purchased disk, etc.. ?

Did you verify the checksum of the iso file prior to burning it and also use the disk verify utility in your disk burning software to confirm the integrity of the file?

David1729 wrote:

I don't remember.

I highly recommend re-installing the OS, which includes re-downloading the iso, doing a md5sum integrity check, on the iso and verifying the disk when it is burned.