Help! Computer laggs on desktop and cursor!

[robbish]

Hey i bought a upgrade kit and now My PC is lagging on the desktop even sound is lagging and ive updated bios and all drivers,could this be a hardware failure? The temps are allright and memtest didnt seem to find anything either,please heeeeeelp!
https://www.webhallen.com/se-sv/datorkomponenter/271757-webhallen_upgrade_kit_i7 That is the upgrade kit and i use a msi gtx 970 and im still using My old harddrives 120g ssd corsair and 1t harddrive

 

[RARRAF]

PSU make and age ??? you re-installed operating system after upgrading ???

 

[robbish]

PSU make and age ??? you re-installed operating system after upgrading ???

 

[robbish]

Corsair 700w Maybe 3 years old and Yeah i reinstalled it :/

 

[RARRAF]

the ASUS Prime Z270-A - ATX / Z270 has the latest bios installed
BIOS
have a fresh formatted FAT32 USB stick download the bios from motherboard manufacturer stick the bios you just downloaded on the USB stick recommend at least 2 bios's re-boot press the delete button repeatedly to get into bios select system update bios select usb device flash it leave it to do its thing then you should be good with new bios
if done wrong will brick your motherboard

 

[robbish]

the ASUS Prime Z270-A - ATX / Z270 has the latest bios installed
BIOS
have a fresh formatted FAT32 USB stick download the bios from motherboard manufacturer stick the bios you just downloaded on the USB stick recommend at least 2 bios's re-boot press the delete button repeatedly to get into bios select system update bios select usb device flash it leave it to do its thing then you should be good with new bios
if done wrong will brick your motherboard

 

[robbish]

Did that yesterday starting to think it might be a hardware issue but im unsure