Internet traffic causes freezing

OK, so i've built myself a Frankenstein PC, Asus P5KC, intel Xeon 5470 (LGA 775 mod), 4x2gb Samsung, Aneon, kingston RAM... And now whenever internet traffic goes up, the comp starts freezing, stuttering and grinds to a halt in a day or two...
Formated Windows from 8.1 to 10. Tried different NICs, builtin lan, double port PCI, single port PCI, WIFI PCIe, all with the same result. Alll the drivers are "up to date" so the wins say... Intel drivers don't wanna install at all (motherboard officially doesn't even support Win7). Temps are OK, SMART doesn't report any (serious) issues, i'm running [email protected] and SETI 24/7, no problems. Drpbx starts syncing, YT video, instant freezing...

Yes, throw that junk away, i know, but i like playing with it :)

Any other ideas?

Change your network cable? Try a USB wifi dongle?

Tried different cables, got an X99 system right next to it and it has no problems with the network. Will try the USB.
But it doesn't solve my problem, i need a fast connection to it, not USB2 XD

why dont the intel drivers want to install?

Don't know... If i manually point to the location, it doesn't find them. Where can i just extract them?

you have the wrong drivers

Yes, u are correct,
they are 20.7.1 for win10, tried everything from 18.3, win XP on, nothing worked...
The latest official drivers for the specific dual NIC are 18.4. Vista, they don't work.
Can u point me to the right ones?

what is the model number and such for your card?

Hardware IDs

8492MT PCI 1000M Network 82546 Dual Port Gigabit Server Adapter For INTEL AU20
Manufacturer Part Number PWLA8492MT

But like i said tried 3 different ones, with the same result.
Also if i disable the builtin one in the BIOS the problem is worse, so it's probably the MB :/

This is a old card. might try the vista driver from here

Don't mean to be rude, but please read my posts if u are replying to them.