1. Slow Computer

When a computer starts to lag behind and seems slower than usual, there are many different causes to consider. Often times, it is more than one factor leading to a slow computer. Some of the main reasons include too many programs set to auto-start, the presence of adware or spyware, cluttered hard drive, insufficient RAM, and registry issues. Depending on your initial problem, typical solutions include running a spyware or virus check, upgrading the RAM, and running a registry cleanup.

2. Poor Internet Connection

The presence of viruses, bad modems, malfunctioning network cards, worn cables, unplugged telephone lines, and corrupted drivers can cause difficult to no connection to the World Wide Web.

3. A Computer That Freezes or Locks Up

A frozen computer, one that locks up, or a PC struck with the "Blue Screen of Death" are all signs of many different things. Most often, registry conflicts, not enough RAM, spyware, file system changes, bad device drivers, missing or corrupted files are behind the problem. Many times, a simple tune-up will get a computer back to reasonable working order.

4. Browser Homepage/Default Search Engine Changes

It is not uncommon to see changes in your browser homepage or default search engine when connecting to the Internet. This is a sign that you have been hijacked – marketing software and viruses are usually behind the changes.

5. Computer Connects to Internet On Its Own

When you find your computer connecting to the Internet without your consent, adware and spyware are common intrusions known to cause this problem. These types of problems have a knack for automatically updating and need to open up an Internet connection to do so. Additional culprits include malicious software and programs, such as trojans, viruses, and worms, as well as "dialers" installed by corrupted websites.

6. Computer Turns On By Itself

When the BIOS is set to "wake on LAN" or "wake on modem," you may experience this type of computer problem.

7. Computer Clock On the Fritz

When a clock seems to lose time, it is a sign that the CMOS battery is dying. The good news – it is replaceable.

8. Random Reboots

When a computer spontaneously reboots, this is a common sign of a hardware problem. While some viruses and trojans can cause this problem to surface, it is often a weakened power supply, RAM, processor, and dirty (or defective) cooling fan) that is the issue.

9. Refuses to Boot Completely

A random conflict or a driver error may hinder a complete boot of a computer. Usually, running the computer is Safe Mode will help pinpoint the issue by only uploading the very rudimentary components required for a computer to function.

10. Noisy Computer

Usually, a moving part that is malfunctioning is the cause of a noisy computer. Sometimes, it is the hard drive or one of the fans inside of the computer. To prevent future damage, you should turn off the machine and check out the source of the noise.