Really Slow Transfer From Admin PC To Laptop

I have 2 desktop computers and one laptop on a network, all three are also part of a Homegroup. When I try to copy files from the main Admin PC to the laptop it slows down to less than 15KB/s. I thought perhaps it was the wifi reception but even when connected with Ethernet it's still terribly slow to the point that a 300MB folder takes 2 hours (estimated time). I end up cancelling the transfer sand sometimes windows explorer ends up crashing. However when I copy files from the second desktop to laptop it is normal speed. No lag, no glitch. All the files I tried to copy where share, available to Everyone. Everything else works fine, streaming video and music from the main admin PC is flawless, I just can't seem too transfer files from the main Admin PC to the laptop.