Adding Reliability (1)
It might not seem obvious, but whenever your system is stressed—lacking resources to accomplish a given task—it also becomes less reliable. Just how unreliable your system becomes depends on the
kind, duration, and intensity of the stress. For example, your system will freeze completely when you run out of memory and there’s no recovery for the problem. Windows will usually try to warn you
about the problem, but many users are so used to simply clicking OK for all message boxes that the system crash becomes inevitable.
Stress need not be as severe as complete loss of memory to cause problems, however. For example, try defragmenting your hard drive when the free hard drive space is less that 10 percent and you’ll
find it takes a long time to complete (if it ever does complete). The problem is a lack of hard disk resources. Even though your hard drive has 10 percent free memory, the disk defragmenter might not
have enough space to move large data segments around and will spend its time thrashing (a condition where an application tries to find enough hard drive space to perform a task to no avail).
Sometimes reliability problems occur even when the system seems to have enough resources, but you haven’t optimized it. For example, some applications begin to act oddly when they can’t request
large enough pieces of memory, even though enough memory is available to answer the request. Windows memory can fragment over time and running too many applications at once only makes the
problem worse.
The bottom line is that optimizing your system can make applications more reliable. Of course, there are various kinds of reliability, and you’ll want to ensure your optimized system provides them all:
?The application starts without displaying weird resource messages.
?The application runs without crashing (even gracefully).
?User settings are tracked properly and changes accepted as anticipated.
?All data remains accessible and intact.
?Data updates always occur as anticipated.
?None of the other running applications experience problems after starting a new application.
Taken From : Microsoft Windows XP Power Optimization