troubles with compaq evo ultra slim desktops

anybody else have issues with these evo, as we call them, slimline computers....1.3 ghz celeron processors????

every single one of these randomly will start to crawl at boot; takes 20+ minutes to get to the desktop. next day they can be fine but inevitably they slow down to a crawl.....

we've wiped the os's clean and started from scratch and the problems keep creeping up....they came with 128 ram but the same problems arise with 392 ram or 256. it doesn't matter....

thanks in advance

dris

Have you checked the power settings? both in the OS and in the BIOS. Maybe cutting back right from the start as it thinks it is idling.