If you need, besides major accounts, an extra account with limited access to data, you can add Windows 8 Guest account. The process is almost the same as in Windows 7.
FreeCommander is an alternative to Windows Explorer. It allows us to work with files much faster and also offers a lot of additional features for more advanced users.
Windows 7 have a nifty feature which combines the windows of opened applications under the same taskbar button. If you don't like it you can always turn it off.
If on your Windows 7 computer opening programs, saving documents, browsing the Internet and other every day tasks are getting slower, this is how you speed up things without installing an additional program.