I've been running Windows 7 build 7100 (d/l'ed from Microsoft.com) for about three weeks now and generally I'm happy with it. However, I do have one big snag that has been bugging me since I did the upgrade from Vista; anything that uses Explorer.exe is extremely slow to render. If I click on Computer, Explorer, Control Panel etc. the window flies out as normal but the contents take around 30 secs or so to populate. If I click on the blank window a "(not responding)" message appears, if I click again the the "windows is not responding - "Wait for the program to respond/Close the program" message appears. During this time both cores are running between 60 and 100%. It could be false perception but I think it actually getting slower! I have the latest video drivers installed (for Vista) but the W7 version fails to install using Automatic Update. All other cpu and RAM intensive apps run perfectly. Hard disks have been defragged, it has been AV checked by the W7 of Kaspersky and spyware checked with MalawareBytes. Any help would be appreciated. My notebook: Acer Aspire 7520 c/w AMD Athlon firstname.lastname@example.orgGhz, 3GB DDR2, GeForce 7000M. *edited to add* Restarting the computer, explorer.exe and dwm.exe makes no difference.