CertiGuide to A+ (A+ 4 Real)  9  Chapter 1: What are Operating Systems and How Do They Work?       9  Operating System Features

Add/Remove Programs 1 2 3 4 5 6 7 8 9 10 System Configuration Tools

Performance Options and Virtual Memory Configuration

The dialog page is split into 3 distinct sections. The first, “Performance”, controls the optimization and page file settings. Clicking the “Performance Options” button displays the dialog in Figure 88.

As an approximate rule, desktop machines should be configured for application performance optimizations, whilst servers should be configured for background services optimizations.

The lower half of the dialog gives you access to the page file configuration. The page file is an area of the disk used as pseudo-memory – when too much data is in use at any one time; Windows copies the least used data from memory and into this area of the disk. The page file concept was originally created when the cost of RAM was high, to allow users to open many applications at once and manipulate large amounts of data that would otherwise not fit in “physical” memory. With the reducing cost of memory, the page file is less important for desktop machines (although it still plays an important role on servers). To configure it, click the “Change” button.

Microsoft recommends that you set the page file size to one and a half times the amount of physical RAM in the machine. It is a good idea to set both the Initial size and Maximum size to the same value, as this prevents Windows from resizing the page file “on the fly”, causing a noticeable slowdown and fragmentation of the disk.

Note the “Registry Size” frame at the bottom of the dialog. The registry will be covered in detail later; however, it is important to know that you can adjust its size here. On rare occasions, the registry may grow to be the maximum size specified here, at which point problems with the system and applications will occur. If this does happen, increase the maximum registry size here to most likely solve the problem.

Note that changes to this dialog will require you to reboot before they can take effect. Cancel the dialog to avoid applying any changes.

Returning to the System Properties dialog, the next option on the Advanced tab is “Environment Variables”. These configuration items provide specific input to any program (including the operating system) that requests them. The most common one is the “path variable”. This tells Windows where it should look for applications when only the executable filename is specified, with no directory. As an example, clicking the Start button, selecting Run and typing “notepad.exe” launches Notepad.

The Notepad executable is actually found at C:\WinNT\System32\Notepad.exe – because the C:\WinNT\System32 directory is included in the path, Windows can find Notepad.exe without requiring you to explicitly type the full path to it. If you moved the Notepad.exe file to the C:\CompTIA folder, we created previously and attempted the same test, because the folder is not in the path you would be notified that Windows could not find the executable. It is quite rare that you will need to alter these environment variables, but it is important to be aware of their existence.

Add/Remove Programs 1 2 3 4 5 6 7 8 9 10 System Configuration Tools