Which chat client to choose?

Question

Chats

Once I was sitting in a Quip in ICQ, but more than one year has passed since then. What to choose now? Looking for client and protocol. Requirements:
- Windows, of course. Even Windows XP
- Rega without a cell phone, because I saw it in a coffin.
- Desirable multi-protocol, as in Quipe
- Desirable clarity and work without perdolinga. Miranda has not the best memories.
- Preferably p2p encryption.
- It is desirable to transfer files.