My WIFI is on limited access, and I cannot connect to the Internet

[Note to Mods: if this is not the right place for this question, please relocate it to the appropriate place, thanks. -CR]

Hi, I have a Dell desktop computer with Windows 7 Home Premium Edition and somehow, up until last week or so, I cannot connect to the Internet and the Wireless WIFI connectivity is automatically set to limited access every time I try to reboot it.

I should also note that while I cannot connect to the Internet on that particular desktop PC, I am somehow able to connect via my laptop and my smartphone.

Below are everything I had done thus far to get the Internet connection restored, along with my observations:

-I am extremely certain that this connectivity issue is exclusive to this particular desktop computer I have. I know this, because my laptop and smartphone use the same Wireless Wifi router and they both work perfectly fine, otherwise I wouldn't be able to write this post.

-Upon booting, the computer never connects to the usual modem that it normally chooses, instead it automatically connects to another similar one that does not exist to my knowledge.

-Whenever I tried to disconnect the computer from that other modem, I would try to connect it to the modem it is supposed to use. But somehow, the computer cannot connect to the modem and instead it automatically connects back to the non-existent one I mentioned earlier.

-I have checked the computer for malware and I found nothing. Therefore, I can rule out malware.

-I have noticed that the computer has been overworking itself despite the lack of any active programs. I have reasons to suspect that something else is running without my foreknowledge.

-I tried to restart the the modem router at least three times and got no connection.

-I tried to connect to the Internet with an Ethernet cable hooked onto the hard drive. Again, no connection.

-I tried to turn off the firewall and tried to connect without out. Once again, no connection.

-I tried to troubleshoot the connection problem it in the control panel and it wouldn't let me.

-Also, whenever I reboot the computer, I keep getting "scripted diagnostics native host stopped working" popups. I have no idea what that means, but it's been showing up before of this happened.

-Currently giving Defragment a go. It has been a whole week since I started that process, and I have no idea if that would even be enough.

-I could try a system restore and bring the computer back to the original factory settings, but something tells me that would be going a little too far.


Right now, I am still trying to figure out how to restore Internet connectivity to the desktop PC. If I am not being specific enough, I apologize. It is because I am not a expert with computers. But I will say this: I am running out of options and in need of help. If anybody here is interested, please let me know and I try my best to elaborate further if needed.