Frequently Asked Questions
Find answers to frequently asked questions about COMClean.
Q: What are the minimum
System Requirements necessary to run COMClean?
A: The following specification is a guideline:
Computer/Processor: PC with 486DX/66 MHz or higher
processor; Pentium or higher processor recommended.
Memory: 16 MB RAM for Windows 95 or later (32 MB
recommended); 24 MB for Windows NT 4.0 / 2000 (32 MB recommended).
Hard Disk: Typical Install: 1MB
Drive: CD ROM Drive
Display: VGA or higher-resolution monitor; Super
Operating System: Microsoft Windows 9x; Microsoft
Windows NT 4.0; Windows 2000
Q: Does COMClean work
on Windows NT?
A: COMClean does indeed work on Windows
NT 4.0 or later running at least Service Pack 3. However,
on Windows NT the registry file size is not reduced when
keys are deleted. To shrink the file you need to perform
the following tasks:
- Export the whole registry to a text file
- Make a second install of NT, to obtain new minimum sized
- Copy the registry files of the second install over those
of your original install
- Start the first install and import the text file to
restore the added entries
Alternatively, Microsoft provide a utility to perform
this task called RegMaid. You can find out more about RegMaid
Q: Is COMClean Shareware?
A: No. COMClean is a fully operational
product. When installed, the user is supplied with an installation
key. COMClean will operate unregistered until this key is
exchanged for a registration key. Please email
us to obtain a registration key.
Q: Does it matter if
I do not register my copy of COMClean?
A: No. However, if you wish to receive
support for the product then you will need to register your
copy of COMClean. Also, unregistered copies do not delete
registry entries. However, there are no other restrictions,
no time limit and no nag screens.
Q: Are there any precautions
I need to take before running COMClean?
A: Be warned that modifying the registry
incorrectly can cause your computer to malfunction which
may result in having to perform a complete reinstall. You
are strongly advised to make a backup of your complete registry
before applying fixes that COMClean suggests. Windows NT
users should use the "Export Registry file.." menu option
within Regedit. Windows 9x users can either do the same
or make copies of the System.dat and User.dat files.
We do not accept any responsibility for corruption
to any computer system that occurs as a result of running
the COMClean application.
Q: What is COM all about
and how does COMClean work?
A: This is a simplified overview. COM
stands for Component Object Model. A client (container)
can call subroutines (invoke methods) in a COM server, which
may be an executable program or a dynamic linked library.
The client asks Windows to create an instance of an object.
Each class of object implements one or more interfaces,
each is a list of methods. The parameters and return value
of each method are specified in a Type Library.
The capabilities of an object are determined by the interfaces
it supports. To help a container determine whether a component
object has the capabilities it requires, the registry may
have information about its Category, such as Control or
Insertable object. All the entities of COM are named with
a Globally Unique Identifier, or GUID, which is a 128 bit
number. The GUID of an object is known as a Class Identifier,
each Interface and each Type Library also has its own GUID.
Objects may have a readable name such as Excel.Application,
known as a Programmatic Identifier or ProgID. To create
an object given its ProgID, programs such as Visual Basic
look in the HKEY_CLASSES_ROOT section for a key of that
name to obtain the object's Class Identifier. Windows finds
the path to the server file in a subkey of the Class Identifier
section of the registry. The GUID of the Type Library may
be specified either in the Class Identifier or the Interface
section. The Type Library section contains the path to the
file which specifies the methods.
If the object can be created on a remote machine the DCOM
(distributed COM) mechanism is used, and the object has
an entry in the Application Identifier or AppID section
of the registry. The interface IUnknown must be implemented
by all objects. At runtime a pointer to any other Interface
is obtained by invoking the QueryInterface method of the
IUnknown interface, specifying the GUID of the interface
required. Many objects implement the IDispatch interface,
from which the Type Library may be obtained.
For a fuller understanding of COM, please refer to the
Technical Overview from Microsoft.
Q: How do I back up
A: The following methods are presented
as guides only:
For Windows 95:
Locate Eru.exe on your computer and execute this file. If
you do not have this file on your system, search your Windows
95 installation CD for Eru.exe, Eru.inf, Eru.txt, and Erd.e_e.
Copy these files to a directory on your machine and then
Run Eru.exe. You will be prompted to back up the registry
to a floppy disk.
For Windows 98:
From the Start button, select Programs and click DOS Prompt.
Type scanreg. This will back up your registry on to your
hard drive. To restore if needed, reboot to DOS and then
type scanreg /restore.
For Windows NT/2000:
Sign on as Administrator. From the Start button, select
Programs, and click Command Prompt. Type rdisk /s. You will
need a floppy disk available to make recovery disk.
Q: Where can I find
out more about troubleshooting Registry problems?
A: The Microsoft Knowledge base provides
documentation on the subject of registry troubleshooting.
Please refer to the Registry
Troubleshooting Article on Microsoft's web site.
Q: What has happened
to RHA (Minisystems) Ltd.?
A: COMClean was originally developed
and maintained by RHA (Minisystems) Ltd. as one of a suite
of interprocess communication controls for Visual Basic
and other programs to aid developers.
RHA (Minisystems) Ltd. are no longer able to provide their
customers with technical support for this utility. As a
result, we have kindly been granted the exclusive rights
to COMClean with a view to not only assisting the existing
customer base that RHA (Minisystems) Ltd. has developed
over the years but to also take COMClean into a wider market.
Our thanks is warmly extended to RHA (Minisystems) Ltd.
for allowing us this opportunity and we humbly acknowledge
Roger Abbott, who authored the COMClean application.