Linksys router problems

It's Firmware that you are referring to.

To find out what version your router is currently using, you would need to log into your Router to find this out.

To Find newer versions of Firmware, you would need to check the Support Section of the Linksys Website and enter your model number. There you can also find other information such as Manuals.

Here is the link for the official Linksys Support forum.

Here is the Link for LinksysInfo.org Forums which is not affiliated with Linksys or Cisco,
but is an excellent source of help.

Here is the site for DD-WRT which is a Custom Firmware for Linksys and other routers,
provided your router is on the support list.

You need to be careful when updating the firmware in your Router or you can very easily end up with a Brick.