Very strange Mouse Lag.

Hello Everyone.

My spec:

OP:Windows 10 64bit
CPU:i7-2600k 3.8ghz
Board: ASUS P8Z68-V PRO
HDD/SSD: 2x 128gb SSD running raid 0 + 1TB 7200rpm HDD
Mem:8Gb 1600mhz ddr3 (4x2gb)
GPU:Nvidia GTX970
PSU:1000w Corsair Hx1050

For the last week I have been plagued by a very strange mouse lag which just will not go away. It happens When moving the mouse left and right on the desktop or when running games. Its a little hard to explain but its like my mouse cursor is hitting an invisible wall on the screen and stops moving for about 1 second. if I continue moving the mouse after that 1 second pause I can move the mouse back to the "Invisible wall" and it'll stop again for 1 second. Eventually the "invisible wall" will disappear and the mouse will move fine until the problem eventually repeats somewhere else!?

I have noticed the problem happens more often around desktop buttons like the start menu, drop down tabs and items that highlight what you are hovering the cursor over them.

At first I though the problem was actually mouse related. (Logitech mx518 and about 5 years old) So I went out and bought a new steel series rival wired mouse. Nope, problem still there! I have literally tried around 25 things to fix this or maybe even more as I've lost track a bit but ill list them below.

• Changed my mouse, Both wired usb mice.
• Cleaned and swapped mouse matt
• Tried all USB Ports, Front and back 8 in total
• Updated Mouse drivers and all other machine drivers
• Changed mouse polling rate lower and higher, changed pretty much all the mouse setting from themes to precision pointer etc etc
• applied a Mark C mouse acceleration fix I stumbled across Online.

No luck at all so I went further and started to blame my recent windows 10 upgrade, I performed a clean install of windows 10 2 times in total... did not help. Eventually I performed a clean intsall of 7 which also did nothing to help.

Now I'm blaming hardware So I have:

• Tested memory with memtest 86+ passed everything.
• Removed my ram and tested each stick in each slot (4x2gb in each slot this took forever!)
• Checked my HDD Health and performed dsk checks - all clear
• Cleaned all dust from the case and fans
• removed my overclock completely (i72600k 4.2ghz back to stock.) Monitored the CPU and heat etc - All good no spikes or anything
• Reinstalled my old gfx card Nvidia gtx580 - didn't help
• Noticed my ethernet controller was not running in device manager so I tried to update drivers etc. this did not resolve the issue so I disabled it.
• Changed to a different monitor.

I have probably tried a lot more things than this as well but Im pretty sure these are the main things. If anyone can help that would be amazing. It could be something really obvious that I'm missing but It is a very strange problem indeed.