Viruses, How to Remove
The message "Your copy of 'application name' has been corrupted or modified by another application or a virus. Please make a new copy from locked master disks." can result from two sources:
1) viruses
2) manually modifying the app. with ResEdit or some other program.
Explanation and Solution
This alert is intended to serve as a warning that there is something wrong. Normally, you can proceed past this alert and use the application. However, as virus-infected software can be unreliable, you should eliminate the infected files from your disks as soon as possible.
It is unnecessary to reformat a hard disk to get rid of viruses. The basic steps are:
* Using a virus detection utility check the hard disk and any floppy diskettes for viruses.
* Trash all infected applications and system software.
* Replace infected files from uninfected locked master disks. If a master disk is infected, obtain new master disks from the software manufacturer.
More detailed and step-by-step explanation:
How viruses are transmitted
There are two main types of known viruses on the Mac. Some viruses embed themselves in the Desktop file (e.g. WDEF). These viruses can be transmitted by simply inserting an infected disk into a disk drive. Other viruses infect applications and system software by infecting them when they're launched or running. For example, when you double-click a Claris application to run it, the virus may immediately infect the application, which will cause the alert to be displayed. If you trash this application, reinstall it, then rerun it, the new copy of the application may become immediately infected. Thus, it may appear that the original disks are infected.
The most reliable way to prevent the spread of viruses is to lock or write protect disks. This is done by moving the black tab in the back of a diskette into a position that allows you to see through the hole. This is especially important for original copies of applications. Please lock all your original disks.
Steps to detect viruses
1- Get virus detection and removal software. These are available as shareware / freeware from user groups and online services, and as commercial software from computer and mail order firms. Be sure to get the latest version of the software.
2- Locate a disk with a System Folder on it, such as the system disks that come with your computer. Lock this disk. Restart the computer from this disk, so that the computer is running from the System folder on this disk.
3- Lock the floppy disk with the virus detection software on it.
4- Insert this disk, then run the virus detection software to check the system disk you used to restart the computer. If this disk is not infected, proceed to the next step. Otherwise, locate an uninfected system disk and start over at step #2 above.
5- Using the virus software, check all original floppy disks for viruses. If any original disks are infected, contact the software publisher for replacement disks.
6- Using the virus detection software, check the hard drive. Set the virus software to remove any viruses from any infected applications and system software. Print or save a report listing all files that have been uninfected.
7- Trash all files from the hard drive that were uninfected in the previous step.
8- Replace all files that were trashed in the previous step by recopying/reinstalling from original disks.
9- Run virus detection utility on the hard drive again to double-check that it's still virus-free.
Tips to prevent viruses
* Lock disks whenever possible. Viruses cannot spread themselves to a locked disk.
* Check all floppy disks before using on your computer. Often viruses are spread because someone ran their software or data files on another person's computer.
* Check data disks given to you. Some viruses can embedded themselves in the directory of a disk. These viruses can be easily transmitted by simply inserting a disk into your own disk drive.