Create a budget and stick to it. How much can you afford to spend on a new computer? Although the prices of computers are decreasing, they can still create a hefty expense especially if you need additional peripherals described above. In addition, you'll need to figure in costs for maintenance, servicing, and insuring. Those errors are the result of Program B attempting to use an outdated (shared) file that was installed by Program A. In order to fix that problem, the user would have to download an updated version of the shared file (which to say the least - is not an easy thing to find or do). Sometimes, errors occur because a system doesn't have the required drivers or the drivers that are on the system are the incorrect version. Even the operating system of a computer has a help file and it really should be the first place to look for answers. Help files are designed not only to guide the usage of a computer, they're also designed to solve problems. Inside a help file, look for a section called, "Troubleshooting" (or something similar) when you need to resolve an issue. So you should install a firewall on the computer that grants access to the computer, and then install an anti-virus and anti-spyware program on each of the remaining computers in the network. If you have files that shouldn't be shared (bank statements, credit card information, etc.), you can restrict their access in one of several ways. Other people have found much more creative and effective ways to use batch files, but the important thing is that you know they're a resource you can use to save a few seconds or minutes in performing important tasks. We've come a long way from MS-DOS, but it's still a valuable source of automation that anyone can use with no programming knowledge at all. One thing that you certainly don't want to use to remove computer dust is a vacuum cleaner. Although using a vacuum cleaner seems to make more sense, the strong suction of a vacuum cleaner can actually spark damaging static electricity or dislodge loose cables. You also don't want to use oil-based cleaners.