Be sure to visit http://www.thenakedpc.com/ and get the newsletter! [TUGPCs Corner is a tiny glimpse into our latest book, "The Unofficial Guide to PCs", (by T. J. Lee, Lee Hudspeth, and Dan Butler) published by QUE (ISBN 0-7897-1797-2).] "Many problems with applications running under Windows stems from something going wrong in the registry. We could fill an entire chapter with bizarre stories about strange application and system crashes that were the result of installing a device or application and having the registry get fouled up. Bright Idea Take this advice to heart, you must have a copy of your registry before you install anything on your computer so you can undo the effects of a bad install if necessary. You need to copy both the User.dat and System.dat files, which reside in the C:\Windows folder. Save these to a disk that you keep in a safe place. Fortunately, there's another System Information utility that can fix problems with the registry and even restore a previous version of the registry. We touched on this utility back in Chapter 9 "Preparing for Disaster." It's such a lifesaver of a utility that a repeat visit is warranted. Registry Checker automatically scans your registry every time you start your computer. If Registry Checker notices a problem, it automatically replaces the registry with the backup copy that it has made (it makes a new copy once a day). You can manually run the Registry Checker from the Tools menu on the System Information program to make a backup copy. Unofficially By default, the Registry Checker keeps five complete copies of your systems registry backed up. This gives you a five-day incremental history to restore from if necessary (unless you manually backup the registry more often). To manually restore your registry, follow these steps: 1. Select Start / Shut Down / Restart in MS-DOS mode / OK. 2. From the MS-DOS command prompt, type scanreg /restore. 3. You'll see a list of the last five backups (named Rbnnn.cab where nnn starts at 000) along with their date/time stamps, so pick the latest known good backup. The screen will also indicate either Started or Not Started for each backup file, meaning that the particular copy of the registry has successfully started your system, or it hasn't, respectively. Pick the backup file you want to restore. 4. Choose Restore. If the restore is successful, Registry Checker tells you so. Likewise if there was a problem restoring the CAB file, an error message appears. In this case try restoring the next oldest CAB. The Scanreg.ini file controls many of the Registry Checker's functions and settings. You'll find this file in your C:\Windows folder. This file can be edited in Notepad and you could, for example, increase the number of backups the checker maintains by changing the MaxBackupCopies settings. For example: MaxBackupCopies=10 This increases the number of copies maintained giving you a 10- day history of your registry files. Be careful editing this INI file as the Registry Checker is a very important part of your disaster recovery arsenal."