|The 1.5 times RAM idea was something that grew up with Windows 98. Windows 98 was a hybrid system of both 16 bit and 32 bit software using both real mode and protected mode CPU operations. This tended to make memory management problematic.|
Windows XP is a 32 bit system that only uses projected mode operations so memory management is considerably easier and a lot more efficient.
Set the page file to let Windows handle it automatically. There should be no need to start manipulating it yourself unless you have some unusual requirements and then you need to know exactly how the page file works and what it does.