Windows XP hints and tips
We take it for granted that Windows and the software installed on the computer can access all the hardware in it and plugged into it, but it's not actually Windows that accesses it. A driver is used, which is special software that acts as an interface or intermediary between Windows and the hardware device. To ensure that a driver is compatible with Windows Microsoft uses driver signing, which is like a certificate to show that the driver is OK.
Click Start and then right click My Computer and choose Properties. Select the Hardware tab and then click the Driver Signing button. A Driver Signing Options dialog is displayed and you can choose what action to take if software is installed - when adding new hardware - and the driver is not signed. If it's not signed it means it has not been certified as compatible. This doesn't mean it isn't compatible and it simply means that it hasn't been tested by Microsoft. The driver's probably fine, but the three driver signing options let you choose what action to take.
Check the digital signatures
If your PC is acting strangely or if you are having problems with it, it could be due to a faulty driver or system file, but which one? Critical Windows system files have been digitally signed so that you can be assured (as far as possible anyway), that they are compatible with the operating system. But what about the drivers and system files that haven't been digitally signed?
You can discover which system files have not been digitally signed quite easily. Click Start, All Programs, Accessories, System Tools, System Information. When the program window appears, select Tools, File Signature Verification Utility. Click the Start button and after the system has been scanned you will see a list of files that have not been digitally signed.
Now close the results window and click the Advanced button. Select the Logging tab in the dialog that appears and click the View Log button. You'll see a more comprehensive results page listing all the files scanned and whether or not they have been digitally signed. It could be useful to save the log when the computer is running OK and compare it when it's not. You'll be able to see the files that have changed and possibly whether any have been changed by malware like viruses, spyware or adware.
DOS isn't dead
It's just hiding. The Windows graphical user interface became popular in the early 1990s and before that all software ran in DOS. This is a text-based environment and you had to do everything by typing in obscure commands at the flashing DOS prompt.
We've come a long way since then, but DOS is still with us, although it's not used much these days. Click Start, Run and enter command.com to open a window and display the old fashioned DOS prompt. It would take a whole book to explain how to do stuff from the DOS prompt, but if you're interested, type help to see a list of the commands you can use. Type a command followed by /? to get help with a specific command, for example, dir /?. Some of the commands are quite powerful and you can do things that are impossible in Windows, which is strange! To close a command prompt window, type exit.
Having told you about command.com, we should say that you shouldn't actually use it. It's only included so that you can run very old DOS software and there's a new version called cmd.exe. Click Start, Run and enter cmd to open a command prompt window. Type help as before to see a list of commands. They are pretty much the same as before, but this command shell is designed for executing powerful commands and scripts in Windows XP rather than emulating an old version of DOS in a window. An explanation of all the commands you can use can be found here. Type exit to close the command prompt window.
DIY startup messages
It is possible to pause the Windows startup process and to display custom messages on the screen. For example, you might want to display a notice stating the owner of the computer,or to display a company name, or some other message like your favourite saying, "To err is human, to really screw things up takes a computer," for example.
Click Start, Run and enter regedit to open the registry editor. In the left-hand pane expand the sections by clicking the plus symbols and navigate to the following key: HKEY_LOCAL_MACHINE\ SOFTWARE\ Microsoft\ Windows NT\ CurrentVersion\ Winlogon. Lots of values are displayed on the right hand side and there are two called LegalNoticeCaption and LegalNoticeText. Double click one or both and enter the text of your messages. Quit the registry editor and then restart Windows to see the effect.
If you want to remove the messages, start the registry editor and return to the key above. Double click each of the two values and delete the text.