Users with WinXP or higher has it very easy. The Windows Prefetcher does most of the job. If you want to know what the prefetcher is, see Wikipedia Prefetcher
and on MSDN the article Windows XP: Kernel Improvements Create a More Robust, Powerful, and Scalable OS
written by Mark Russinovich (SysInternals, you know) and David Solomon.
What I additionally do on my WinXP computer is following:
After installing the monthly Windows security updates (released on every second Tuesday of the month) and rebooting Windows I delete all the temporary files in the temp folder(s) and some other temporary files, caches and not needed uninstall informations of the security updates. Important here is to delete all files in the Windows\Prefetch directory permanently (not to trash). You can trust me this is safe.
The prefetcher makes now the next 2 weeks its work and collects the data how to organize the files best to start it fast. 2 weeks after deleting all prefetch files including Layout.ini I delete again all the files in the temp folder(s) (only 1 on my computer because I have deleted the users TEMP environment variable). Then I run manually the defragmentation tool of Windows XP. That's it.
For my other computers with Win98 and Win95 and also for WinXP, I do following after installation of a new version:
Move the whole program directory of the just installed program to a different drive. Then I defrag the programs drive after deleting all the temp files. Then I copy back the program directory, defrag the programs drive again and last I delete the copy of the program directory on the other drive. If you have Win98 and you watch the details during defragmentation you will see that the files of the program are now in the same area. If you want that perfect, you could log with Filemon in which order which files are loaded and copy that files in this order from the other drive back to the programs drive. But I don't do that.
Above is just a little hint to get programs faster. It needs much more to get whole system permanently fast. But its useless to tell you in detail how because it is required to apply the "keep your computer fast and clean method" from the beginning on. Before you install Windows you have to divide your hard disk into at least 4 partitions:
- a system partition with the OS and the smaller programs regularly updated
- a program partition where big program suites like MS Office are installed
- a small data partition where your data files are stored
- a partition for temporary files
Usage of more than 1 hard disk would be even better, but I don't need so much space for my work.
After installing Windows many registry hacks and modifications must be done to make sure that all temporary files including the files Internet Explorer, other browsers and programs create temporarily are created on the TEMP partition. Program suites must be installed with custom setup to the program partition, small programs are installed with custom setup either to the system or the program partition. All programs must be setup to use directories on the data partition for files I create or edit. (There was never a file in "My Documents" on my WinXP except the pre-installed ones.) And much, much more. With such an effort before and after every program install you can keep the 2 program drives fast. Most computer users need only a few minutes or even seconds to install a program. I need always at least 30 minutes, on first install much more to install and configure it perfectly for my needs. But I got this time back within next 3-7 days because of more efficient work. Nobody in my department is as fast as I when manipulating data. The configuration and deep knowledge of the tools I use makes the difference.
The data partition is regularly (every 2-3 months) completely copied to the temp partition, quick formatted and then all is copied back (after using UltraSentry to destroy all data bytes on the empty data drive after the quick format). Data not needed anymore daily are packed with RAR (decrease number of files and space). The partition with the temporary files is once per month simply quickly formatted which require a booting from another device because of the index.dat files on this drive. That's why my temp drives are FAT32 partitions which I can quickly format with a Win98 floppy boot disk. (UltraSentry is again used to really clean this drive after formatting).
My WinXP is 6 years old and as fast as on first day. All my colleagues complain periodically that their computers are getting slower and slower and slower and they want a new computer (and some have got it), a larger hard disk (and most of them bought it from their own pockets), more RAM (some got it), etc. But my unmodified computer is still faster than there upgraded computers, although I was forced twice to get my computer into a completely new network environment with additional program changes (Outlook, ...). As long as they don't change how they manage their programs and files, a new hardware will solve their speed problems only for the next 6-12 months. That's what I think.