Windows 7 slow performance

[mmccaws]

One indicator of Windows 7 slow performance on my machine is the way it handles the files in the "Downloads" folder. When i open Downloads folder, the file shows no files, even shows no file count. Then after refreshing it, a green bar starts to form in the location directory. The bar grows, lengthens, till it completely spans the location bar, then it shows the files., all 108 items. This has taken from less than a minute to over two minutes. What possible setting would hide the file names in the first place. Why would it take so long to build the list. is something scanning these each time?

Thanks

Mike