Using 2 android devices - Nexus 4 running Android 4.2.2, and a Motorola XOOM tablet. Up until about a week ago or less, both could login into my desktop PC (running Win7 64 bit) over WIFI (router ASUS RT-N56U) to transfer files, etc.

Suddenly a few days back, they can no longer login. They are hitting the router fine, can use the internet, etc. They can see the PC's IP address in a search, but when I try to login to the PC from the phone, it fails. I've tried using several file managers on the android devices (ES file Explorer and a few others, just to see if the app was the problem), but same result on both devices.

Wondering what could have changed. I didn't change any router settings, and when I look at the PC, the folders are still shared - I can get to them from my Windows laptop.

I tried deleting the "found" network inside of Android and re-searching. Again, it sees the network, and the PC's IP address on the home network, but can't login to it.

Any ideas on what to check next?