Computer issues.. cant connect to proxy and everythings messed up?

[Sin with a Grin]

So for the last week my computer has been having a hard time connecting to "the proxy server". My internet isn't as speedy as it used to be. In fact, I'm lucky if YouTube gets me about four seconds before not working anymore.

Im connected the the network, and its all five bars. But my internet is horrendous. I can't connect to the iTunes store (even though I'm connected to the internet).

Xbox Live and PSN work just fine. Both are not connected to the internet right now.

Is there anyway to fix this? I've tried restarting the WiFi and that doesn't work.

If this is of any importance, I'm using Windows 8.

[Adrian]

Most home users never use a "proxy", so why are you using one? Proxies are often slow, unless you have bought a commercial proxy service. Also, many viruses can set proxy settings to point all your browsing via the hacker's web proxy. Do a full virus scan...

[Sin with a Grin]

Damn. Okay. On the chance that there's nothing that indicates that there's anyone fucking around with my computer.. is there a way to restore the computer to factory settings and if so, would it be "safe" to do that?