My sister is still on XP (I know updates are ending very soon, and I am going to try to talk her into upgrading - she's just afraid she'll have problems with the software she uses, settings for it, etc. Anyway, she does have good third-party solutions installed for virus and malware protection. So, that's for another day.) Recently she started having trouble connecting to the Internet on the computer upstairs. There were two separate modems that connected to the internet independently in the household. The one downstairs works fine (her son's). She even went and picked up a new modem because it seemed like that might have been the cause. It worked for a short time (seemed like a few hours from what I could gather), but then she started having the exact same problems in that it wouldn't connect, which made me think the problem might be with her nic port. She picked up an 802.11ac adapter - this one: www.dlink.com/us/en/home-solutions/connect/adapters/dwa-182-wireless-ac1200-dual-band-usb-adapter at a local store, and the computer downstairs has an 802.11ac router (Asus RT-AC66U). She can't get it to see the network on the XP computer upstairs. Usually I would connect by remote desktop and help her with PC issues, but I can't do that with this, of course, and I am not getting anywhere trying to get it working over the phone. It will just never show the network in range to connect to. BUT, she borrowed a netbook from a friend, plugged the exact same USB adapter into it, and it connects to the network fine upstairs. So, it'd definitely in range. Any ideas why the XP system won't see the network downstairs? I was sure to tell her to disable the other network connections. Nothing seems to help so far. Thank you much in advance.