PC Really slow for no reason

so recently i had re-installed windows on my pc and in doing so i had to reformat my drives from gpt to mbr cause it wouldnt let me install windows on it unless it was mbr but found out that it had to be gpt when windows was installed so i used the built in MBR2GPT.EXE to re format it to gpt and my pc is really slow to the point where i can barley run my pc with my browser and discord open i thought it was because i had a bad gpu so i put 2 gpu's in the pc which did not resolve my problem so then i scanned my pc for corrupt windows files which there was but it did not help at all i tried deleting applications and force closing background apps which also did not work i have even tried adding more storage, my ram is at 32gb so its not a ram issue it is not a cpu or gpu issue what could be the issue ? i have litteraly tried just about everything