Netscape is not a very effient program, by its very nature. It uses a lot of memory, a lot of disk space, a lot of CPU power. What makes it worse is, its default configuration makes it even less efficient than it needs to be. When it reads something from the net, it writes it to its disk cache then back from there to the screen. If you go forward to a new page, then back, it reads it from disk yet again. This is wastefull, buth of time and disk space. Even with today's multi-gigibyte hard drives, there's no need to waste space like this. Not only that, there are programs that can read your disk cache. If you share your computer, any body else using it can see what you've been looking at. Granted, they can also tell what sites you've visited by examining your history file, but that only lists the site's names, not the content.
To fix this, have Netscape open. Click on Edit, then Preferences. In the list of catagories, click on the plus sign next to Advanced, to open it up. Click on Cache.
First, clear your Disk Cache. This will delete all files in your disk cache, recovering the space and preventing snooping. Then, set your disk cache to zero.
Next, set your Memory Cache to six megabytes. As Netscape measures in kilobytes, that's 6144 K. Click OK to activate these changes.
These changes will lower your disk activity in Netscape by at least a factor of 3. When you click on Back, the page comes up so fast, you won't believe it at first. Try these simple chages to Netscape; I'm sure you'll find them a vast improvement.