Find and Replace functions in software such as Word and Notepad are very useful when replacing a large number of textual items with different text. Particular packages such as Word also allow more advanced find and replace using wildcards. However, this is just the tip of the iceberg. Find and replace becomes most powerful when used in conjunction with regular expressions. Regular expressions allow you to identify strings by constructing an expression. This is a format of pattern matching, meaning that you provide a pattern in an expression and the computer can then identify strings of text which match that pattern. Regular expressions are extremely useful, and can be used to identify patterns of almost any string you can imagine. For more information on regular expressions, check en.wikipedia.org/wiki/Regular_expression . Additionally, a very good free find and replace utility which implements regular expressions is TextCrawler, available from: www.digitalvolcano.co.uk/textcrawler.html . I recently used regular expressions and TextCrawler to remove garbage text from a text file during the migration of data between databases and found it to be an excellent utility.

For the past few months whenever I boot Windows XP a balloon appears saying that my computer is at risk because the Windows Firewall is not enabled. I click the balloon to open the Windows Security Centre and it recommends that I enable the firewall, which I have been doing. However, when I shutdown the computer and startup the following day the same problem occurs. Has a virus crept into the computer which is turning off the firewall overnight? (more…)

When changing the display settings through the “Display” control panel “Settings” tab I am not asked whether I would like to keep the settings. How can I fix this problem? (more…)

Taking screen shots is a very useful function, especially if you wish to explain a certain function to another user or are compiling a user guide. The in-built Windows screen shot facility (using the PrtScn button) is simple, but is also limited to only taking shots of the entire screen, or a particular window, and then having to paste the screen shot into another application. An excellent free screen shot utility is called Lightscreen. This is a very lightweight program allowing you to take screen shots of various different areas, and save them in a range of formats (including the loss-less PNG graphics format). Lightscreen is available for free download from: lightscreen.sourceforge.net .

A few weeks ago my internet modem died, and was replaced. Now I am unable to use Javascript to access the crossword puzzles on the Sydney Morning Herald website. Instead, a message appears saying that the computer does not support Javascript or it has been disabled. In an attempt to fix this problem I uninstalled Java, but cannot find where to download and reinstall the Java program from the internet. Another computer on my home network does not have any problems with the crossword website. The computer is running Windows Vista Home Premium. (more…)