Internet Connection (Vista Ultimate)

[ExoriaX]

Hello all,

I seem to be able to get rid of limited connectivity in IPv4 by change the speed from Auto Detect to 100MB Half Duplex. I have disabled IPv6 because all computers/routers in this house works with IPv4 only. It's also because IPv6 is showing Limited Connectivity, but IPv4 works great.
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Status:

Access: Local and Internet
Connection: Local Area Connection
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It is showing that I'm connected to local and internet. Yes, everything works great, but when I want to upload 2 files to www.mediafire.com, a free file hosting site. When the files are uploading for maybe 5-10 mins or less the internet connection stopped working, Xfire (an instant messenger) disconnected and Firefox doesn't work. The most odd thing is that the internet connection still said that I am connected to Local and Internet.

This always happen when I want to upload some any files. Also right before the internet stopped working the mediafire opened a page during the uploading and said "the browser doesn't support redirects..." then bam internet doesn't work, of course the internet connection still said that I am connected to Local and Internet.

To get internet back to work again is restart the computer. Repair doesn't work. Disable/Enable the network adapter doesn't work either. It won't even let me to disable it.

So, how can I get to connect internet constantly during uploading and etc?

Any suggestions appreciated.

Thanks,
ExoriaX

EDIT: I have tried to run safe mode with network capable. It does the same thing so what is possible to cause this problem?