1)   Auslogics BoostSpeed 4 4.5.15
If your computer or Internet feels slower than usual, Auslogics might have a remedy - its award winning Auslogics Boost Speed. The program cleans up and defragments disks and the registry, speeds up the Internet, and keeps your PC running error-free.

 2)   PC Speed-Boost Toolbar 1.3
PC Speed Boost & Registry Fix Toolbar. The All-In-One PC Mechanic! The PC Speed-Boost Toolbar is a browser addon that instantly boosts your PC performance with free registry scanning, spyware scanning and ad-blocking tools for faster browsing.

 3)   MyRegistryCleaner 3.3.4.26
Is your PC slow? Fix the problem with a quick download! Tune Up your PC, clean, repair, speed up and back up your system. All in one! Let your PC run fast and clean again. It's that simple!

 4)   AusLogics BoostSpeed 3.7.3
BoostSpeed keeps your PC running as fast as possible. It will boost Internet connections, clean the registry and disks, increase Windows performance, etc. Turbo-charge your PC in minutes!

 5)   !xSpeed 5.0
Fantastic tool to speed up windows or speed down windows -256~+256 times, All software (such as games or movies) will change their speed after you adjust the speed rating in !xSpeed.

 6)   Free PC Boost Fix 2.1.0.0
Free PC Boost improves the performance of your Internet connection through specially engineered software designed to optimize your Internet connection regardless of its type – dialup, LAN, DSL.

 7)   Cacheman 5.50
Cacheman is a utility designed to improve the performance of your computer by optimizing the disk cache, memory and a number of other settings. Cacheman is able to prevent frequent paging to the hard disk, resulting in improved performance.

 8)   Fresh RAM 5.0.0
Try out for free our powerful, easy-to-use and feature filled memory optimization solution and see for yourself the overall performance gains that you computer will benefit from.

 9)   Windows PC Tweaker 2010.05.2
All-in-one tool for optimizing your PC, Windows PC Tweaker offers complete solution for Windows users who want to tweak PC system to the optimal performance. Repair problems, clean up drive space, optimize system, apply Windows tweaks and more.

 10)   PC Optimizer Pro (pc speed up suite) 4.74
Designed for novice users who value their time, PC Optimizer Pro is powerful software that tweaks, repair, and speed up PC, preventing it from crashing and protecting from theft of your important data.

 11)   My Faster PC 5.3
Find and repair errors, clean and defragment your hard drive, optimize PC settings, and more! My Faster PC is a powerful system diagnostic utility that helps you clean your PC for optimal performance.

 12)   Speed Up My PC Widget 1.01
Shows your CPU and memory consumption in two gauges (like a car speedometer). From that information, you can see how you need to speed up my computer. Computer speed is shown on the left gauge, memory consumption on right.

 13)   Free CD Replicator Fix 2.1.0.0
Free CD Replicator is designed to ensure that you can convert any audio file into any possible format so that you can play the music in your car, on your MP3 player or most flash based players.

 14)   Why is my computer so slow 1.0
Resources designed to help people solve slow PC performance issues, and speed up their slow PC.

 15)   AVS Registry Cleaner 2.1.1.217
Scan, clean and fix Windows registry and PC entries with AVS Registry Cleaner. Remove trash files from your system and speed up its performance! Scan DLL files, search for broken links and corrupted applications.

 16)   Digeus Registry Cleaner 5.4
Digeus Registry Cleaner is a PC maintenance and recovery tool that eliminates system error messages, slow startup and shutdown speed, programs instability and computer crashes.

 17)   Speed Up Your PC - PC Booster 1
PC Booster - Fix That Slow PC. PC Booster is an interactive eBook designed to help you get the most out of your PC. If your PC has started to become slow, or your receive .dll errors or all programs are taking ages to load then use PC Booster.

 18)   Slow-PC.com 1.0
Resources designed to help people solve slow PC performance issues, and speed up their slow PC.

 19)   SpeedUp Pctool 3.4
SpeedUp Pctool is the most recommended Software. Helps to Speed up Internet, Optimizes RAM by Cleaning unwanted browsing history and junk files Speedup PcTool is an award winning program to speed up Pc and fix Registry Errors

 20)   Get ACA Utilities to Give Your PC a Speed Boost! Take ACA Utilities for a Spin Today Ebook 1.0
Found this interesting site that gives useful tips on keeping your PC in great shape by using a performance improving utility package called ACA Utilities. I'm sure you will find a hint that will work for you.