PO are taking 5 mins to print preview

i create a new PO and then go to print preview or even print. it take 5 mins before it show up on screen and may not print if i tell it to just print, i am think i have a lot of temp files in my own users files, we are running on server 2012 R and on thin clients. any idea how to clear that out, and see if that speends up Printing of po?