Uninstall Programs Manually in Windows OS

Just because Windows XP has the Add/Remove Programs feature it doesn't mean your application will appear in the list. Furthermore, even if it does appear, it's no guarantee that the uninstall feature will work. When you run across one of these situations the items listed below will help in getting rid of the application. Be aware that these steps may not remove everything associated with the application and can impact other applications on the computer. Have a backup or restore point and use caution.

• Find the directory for the application and delete all the files in the directory. Delete the directory.

• Open regedit and navigate to HKEY_LOCAL_MACHINE\SOFTWARE and find the folder for the application. Delete the folder.

• Open regedit and navigate to HKEY_CURRENT_USER\SOFTWARE and find the folder for the application. Delete the folder.

• To remove the application entry from Add/Remove Programs (if present) open regedit and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall and find the folder for the application. Delete the folder.

• Some applications have Services attached to them. If this is the case, navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services, locate and delete the service.

• In Windows Explorer, navigate to the individual user settings and delete program references. Common places to check would be:

C:\Documents and Settings\All Users\Start Menu\Programs and delete relevant entries.
C:\Documents and Settings\All Users\Start Menu\Programs\Startup and delete relevant entries.
C:\Documents and Settings\%YourUserID%\Start Menu\Programs and delete relevant entries.
[Do this for each User ID listed]
C:\Documents and Settings\%YourUserID%\Start Menu\Programs\Startup and delete relevant entries.
[Do this for each User ID listed]

If no entries were found in the previous step and the application launches automatically, navigate to
HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
and delete the entry.

OPC

Origin and Uses

The OPC Specification was based on the OLE, COM, and DCOM technologies developed by Microsoft for the Microsoft Windows operating system family. The specification defined a standard set of objects, interfaces and methods for use in process control and manufacturing automation applications to facilitate interoperability.

OPC was designed to bridge Windows based applications and process control hardware and software applications. It is an open standard that permits a consistent method of accessing field data from plant floor devices. This method remains the same regardless of the type and source of data.

OPC servers provide a method for many different software packages to access data from a process control device, such as a PLC or DCS. Traditionally, any time a package needed access to data from a device, a custom interface, or driver, had to be written. The purpose of OPC is to define a common interface that is written once and then reused by any business, SCADA, HMI, or custom software packages.

Once an OPC server is written for a particular device, it can be reused by any application that is able to act as an OPC client. OPC servers use Microsoft’s OLE technology (also known as the Component Object Model, or COM) to communicate with clients. COM technology permits a standard for real-time information exchange between software applications and process hardware to be defined.

Future

The OPC Unified Architecture (UA) has been specified and is being tested and implemented through its Early Adopters program. It can be implemented with Java, Microsoft .NET, or C, eliminating the need to use a Microsoft Windows based platform of earlier OPC versions. UA combines the functionality of the existing OPC interfaces with new technologies such as XML and Web Services to deliver higher level MES and ERP support. It looks to become the standard for exchanging industrial data, replacing FactoryTalk, Archestra, some Modbus applications, and OPCDA.