It stands to reason: the less software you have on your system, the lower the risk of software conflicts.
Windows 7 is complete enough to not need any added helper programs. The Windows Firewall, Security Essentials, Windows Update, and other components of Windows 7 are sufficient to keep your machine running smoothly and virus-free.
(Technically, Security Essentials is freeware supplied separately by Microsoft, but I consider it part of the operating system.)
In the past, I have recommended free file-management programs for Windows Vista and XP to replace or enhance Windows Explorer. Windows 7 Explorer is not a big departure from its predecessors, but with a few tweaks it can meet the file-management needs of most PC users--no add-ons necessary.
These changes to settings can improve Windows 7's performance and reduce the amount of time you spend accessing and managing files. Save even more time by using Explorer-specific keyboard shortcuts to change views and navigate between files and folders.
Speed load times by switching off thumbnails
Who has time for folders? I prefer to throw all my files onto the desktop. With thumbnail view enabled, it can take several seconds for thumbnails of files to appear as I scroll through a folder.
To reduce scroll times, switch to viewing faster-loading file icons by disabling thumbnails. You do so by changing an entry in Windows Explorer's advanced settings.
To open Windows Explorer's advanced settings, press the Windows key, type "folder options" (without the quotes), press Enter, and click the View tab. To give thumbnails the boot, check "Always show icons, never thumbnails" in the advanced settings window.
The Windows 7 Forum describes three other ways to disable thumbnails in Windows 7 Explorer.
Before you make this change, consider that when thumbnails are disabled, you can't preview image files in Explorer's preview pane (toggle the preview pane by pressing Alt-P). An alternative is to keep thumbnails enabled and press the Ctrl key while using your mouse's scroll wheel to cycle through Explorer views.
The Windows 7 Help Site explains the other advanced settings in Windows 7 Explorer. The advanced options I enable include "Always show menu," "Display file size information in folder tips," and "Automatically type into the search box" under "When typing into list view."
I leave unchecked the options to "Hide extensions for known file types" and "Launch folder windows in a separate process." Viewing file extensions makes it easier to spot malware, and system performance can take a hit when too many processes are running.
Jump around Windows 7 Explorer using the keyboard
Pressing Alt-P to toggle Explorer's preview pane on and off is far from the only useful keyboard shortcut for the file manager. The Windows 7 Help Site lists the keyboard shortcuts built into Explorer and other Windows 7 components and utilities. Here's an abbreviated list of the handiest keystroke combinations for Windows 7 Explorer.
Alt-up arrow: view the parent folder (Backspace in XP's version of Explorer)
Al-right arrow: view the next folder
Alt-left arrow: view the previous folder
Alt-D: move to the address bar
Alt-Enter: display the Properties dialog for the selected item
Ctrl-Shift-N: create a new folder
Ctrl-Shift-E: display all the folders above the selection
F2: rename the selected item
F4: display the address bar entries
Alt-F4: close the active item or program
Ctrl-F4: close the active document
F6: cycle through screen elements