That's not the issue. But it can cause ALL versions of Windows to be sluggish since Explore wants to read each file to pick up a thumbnail or other data from the files in the folder you opened.
Unless you clean the files off the PC, Explorer will continue to work hard to deliver icons and information as you open folders.
Why do you need to use Explorer? Maybe a lighter weight more nimble file/folder browser will do? I often suggest Gyula's Navigator when we need to get around faster. There are others too.
Cnet forums I have a computer that is 18 months old running Windows 7 Home Premium. It has a Pentium dual core CPU ES 300 @ 2.60GHz, a 310GB HDD and 2048MB memory. Operations have drastically slowed down and each time I select a folder or file from Windows Explorer I have to wait whilst the address bar at top of the screen slowly turns green before a file can be opened. and also some files/folders become non responsive, not always the same ones. When this happens a re-boot is necessary as task manager will not open at this time. The Internet connection accepts anti-virus and spyware updates, music/video downloads and Skype conversations but will not open Internet Explorer or Firefox. The trouble shooter tells me that 'the DNS server is not responding' but my ISP insists the problem is at my computer. I tried to re-install the OS but was told the installed programme is newer, probably by updates, and could not do this. I have a portable 500GB hard disc that is only ever used for a weekly back-up using the W7 in-built programme and this ibecame 99% full so I guess this back-up programme does not overwrite the previous ones. I have just reformatted this and the first back-up of C drive containing 166GB needed 180Gb of space. Any advice on how to overcome these problems would be greatly appreciated. Gerald Gibbons