No.Even if you have a Genie DVR in the home you cannot pause live TV with an H25 receiver. However, there are some things you should probably know.
What most people do as a workaround is record the program on the Genie, then it can be played from the Genie playlist and you can pause it even though it’s live.
If you go to a hotel and your room has an H25 in it, you may be able to pause live TV because some hotel H25s are fitted with flash drives that let them pause live TV. Even if you stole the flash drive from them (don’t do this) it won’t work in a receiver designed for home.
In short there is no way to upgrade an H25 so that, by itself, you can pause live TV. If you want to upgrade to that functionality, replace the H25 with a Genie Mini Client (if you have a Genie DVR) or with an HR24 DVR if you don’t.
Thanks to Signal Pro Jason for this suggestion!