Can computers lose information?
It depends on what "memory" you are talking about. Basically, nothing in a computer can contain data forever. Random Access Memory in a computer loses its data after it is no longer powered, a hard drive has a data retention of approximatively 10 years (this may be different now because of SSDs/SSHD/etc, but you get the idea). There are also several cases where a memory becomes amnesic, but knowing that there are many types of technology for memory, it can vary greatly. It is sometimes possible de retrieve lost data, but again, it depends on the technology.