My help for you is to provide tips about the order of steps to take when troubleshooting your issue, that will allow you to proceed through an unknown problem safely to find a resolution, without doing more harm than good. The main thing you need to know nowadays, is not to give out your credit card information to ANYBODY online. I saw one this week that said it was the FBI locking your computer and you had to pay a fine online in order to get it unlocked (pretty clever) BUT NO, the FBI is not in that business, if the URL says epaypal.com, it is not paypal.com don't click on anything fake or asking you for money. The best advice I can give you, when a window pops up that you didn't ask for, or don't understand, just log off your computer and back on again. This only takes a moment and can save you hours of frustration.
If you are the type of person who believes that an ounce of prevention is worth a pound of cure, do this: Download Clonezilla http://clonezilla.org/ and make your own bootable Linux CD that is all set up to copy the ENTIRE image of your computer to a single file, which you can keep on an external hard drive. A good backup plan would be to image each of your computers twice a year and then move your new files to that external device about once a month. Be sure to keep this device in a separate location from the PCs you're backing up, so they don't both get ruined in the same disaster. If the worst happens to your PC, you can get it back to the way it was, by booting again from the Linux CD and copying your image back onto your computer.
Another, simpler strategy that can fix about 2/3 of computer problems is to make sure your System Restore is turned on. This takes occasional snap shots of your system and lets you set your computer back to the way it was last week, or last month. Knowing you can do this, gives us all more confidence to try changing things on our computer, uninstalling software we don't think we need, or installing new software we think we do need. When it turns out not to be what you thought, just restore your computer to last week and you're good again. For the most trying cases use this tip: http://www.techrepublic.com/article/launch-system-restore-from-a-command-prompt-in-windows-xp/6134546
which also works in Windows 7 and 8.
If you still have a problem that isn't getting cured by System Restore, don't give up!
First, use Google Groups http://groups.google.com to search UseNet for a discussion of your issue. Simply copy and paste the text of any error message with "quotes" around it and find threaded discussions relating to your issue. Often, the answers are all right there, with links to other sites provided. You're not the first person to have your problem, so let the internet help provide the solutions.
Second, run checkdisk, a utility on your PC that cleans up the physical space on your hard drive and synchronizes the index of that information back to the software index of your system, many problems go away with this cure.
Third, update your antivirus software and run a scan and fix.Microsoft offers a free virus software called Security Essentials which I recommend, choose it in Ninite updater below. Then, download Microsoft's Safety Scanner http://www.microsoft.com/security/scanner/en-us/default.aspx and let it run a full scan. If these don't help, try www.antivirus.com and use their free scan and repair for home users. Fourth, you can keep non-Microsoft updates current with www.ninite.com a quick way to keep your machine safe and running the latest versions of internet software.
Last, it might be quicker, if your files are backed up, to boot from your restore CD and set up your PC again from scratch. If you suspect your hard drive is worn out, you can replace it with a new one before restoring, and often use your old drive as a slave (drive D:) to recover files directly off it by copying them to your new C: drive. Be sure to write down your key information first!
Stay tuned to this page for more interesting tips and links and useful advice.
Recently, I read an article which says desktop computers are for production, like in a business environment, create a document, spreadsheet or presentation, for instance. Whereas, the new smart phones and tablets with a mobile/touch interface are more about engaging users in media or social contexts, so easy access to music, video, e-books, e-mail, internet, Facebook, Twitter, etc. I think it helps to think of these as two separate digital technologies, that are set up and used in different ways. Think of ways to engage student with the technology that is designed to ease engagement. Apps like www.exitticket.org
make this easy to pursue.