Slow computer

My computer has recently started moving much slower than normal. It occured right after I moved my mother board from one case to another. I've reinstalled windows and even blew out my computer completely free of dust. Now I have troubles installing things because it goes soooo slow. My sound is all choppy. When I watch videos occasionally the video and audio will slow down. I can't even play The Sims anymore. Can anyone give me a little insight on this situation?

 

Did you install the mobo chipset drivers? as these can make a heck of a difference.

 

Thing of it is this started happening after I tried to move my motherboard from one case to another, but it didnt fit so I moved it back. Nothing changed, but as soon as I booted it back up it started doing this, but it was working fine before. I'll check out if I can find the drivers, though. It's an older motherboard so it might be kind of hard. Assume that the drivers don't work for now, though. What is the next course of action?

 

I'd check that everything is plugged in properly - especially the RAM. I'd probably then format the HD and re-load the OS.

 

Tried it, didn't work. If this helps at all, when I watch movies it'll start out going pretty slow (extremely slow when I'm downloading) and the sound will be going slow, then after a minute or so it'll play through with little or no problems. I watch them in AVI format so it isn't the cd-rom, and I used to be able to watch them just fine with no problems until I attempted to move the mobo.