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Windows Defrag Tip
~~Vic Ferri, WinTips and Tricks

This applies to Windows 98/98se/ME only.

Customize Applog

First of all, a brief explanation of what applog is all about:

Applog stands for Application Logging which, as its name makes clear, is a logging of information about the applications you use. This logging is performed automatically by the Task Monitor (taskmon.exe) which loads every time you start Windows 98 or Me, and is constantly running in the background, with the sole purpose of keeping track of your program activity. Just like Applog, the name TaskMon makes it's use clear - it monitors your tasks. Whenever you open a file that is determined to need logging (i.e. a program) a disk trace is activated by the driver fiolog.vxd and a log file is created in your Windows APPLOG folder. The log files reveal the programs you used along with their supporting files and paths. They also contain cluster order information. This cluster information is generated by a dll file named Clusalgo.dll, and yet again, just by the name of the file, you can get clues to the fact that it logs (lgo) application (a) clusters (clus). All this information is used by Windows Defrag to determine how to optimize your hard drive so that your most frequently used programs (as suggested by the log files) load faster. When you start Defrag a file named Cvtaplog.exe loads first and communicates with clusalgo.dll to give Defrag.exe the information it needs for the optimization.

According to Microsoft "Disk Defragmenter uses the log files to arrange program files in the order they are accessed when the program starts, causing the program to start more quickly."

This is done by moving the programs and their supporting files to a single contiguous area of the hard disk - usually the front of the disk from which file access is quickest.

Note that this is not an essential service - you can disable taskmon and/or delete the Applog folder to defrag your whole drive in a standard way with no special programs taking priority.

The APPLOG Folder

To see your Applog folder, just click Start>Run, type APPLOG and click Ok - or just go to your Windows folder to find it.  Make sure you have Show All Files enabled as it is a hidden folder, by default.

If you take a look inside the folder, you will see numerous files beginning with the name of program files and having extensions like lgc, lgd, lge, etc.
Example: notepad.lgd
The lg stands for log.
The d stands for the d: drive
This would mean that notepad was used on the d drive

If you open any of these log files with any text editor, you will see that they are mostly readable. You will see the files and paths that have been tracked.  The notepad.lgd example might contain something like this:
"D:\BACKUP\TIPS.TXT"
This would indicate notepad was used to open the file tips.txt in the folder Backup on your D: drive.  The log files also show any supporting files that were needed by the program.

OPTLOG.TXT

You will also find a file named OPTLOG.TXT in the Applog folder. This file lists which programs have been optimized by defrag (under the section "Programs Eligible For Optimization").  Also listed are files that were logged but could not be optimized. This information is under the section "Programs Ineligible For Optimization" and the reason for the failure is flagged as follows:

S Log size smaller than 1000 bytes - the default
U Program not used for more than 90 days - the default
P No profile for program
E Associated program no longer exists
D Log deleted (may be combined with one of the above)

Files you see that end in dtc, dtd, etc. contain the cluster placement information for defrag to use. The last letter of the extension stands for the letter of the drive containing the cluster info.

All this may sound great for optimizing your programs, and it can be, but a common problem with this app logging is that it can't be as smart as you would be in choosing the programs to optimize. Even programs you only used temporarily with no plan to use again can be logged. Obviously, these aren't the programs you want defrag to waste it's time optimizing. Nor would you want defrag to optimize little programs like notepad or calculator which are so small that optimizing would be quite useless. The default is 90 days before a file is considered too old to be optimized. This means that even programs you may have just used a few times a couple of months ago can be included for optimizing. This results in very inefficient and wasteful optimizing. A better way, is to customize what gets optimized on your own. Following is how and as you will see, it is extremely easy to do.

Customize the App Logging

1. Before defragging your hard drive, delete the entire contents of the Windows Applog folder so it is empty.

2. Then open and close - at least three times - each program you wish to have optimized. Of course, you would be choosing the programs you use most often - especially the bigger programs.

Note - to be sure the program gets logged, check inside your applog folder.  i.e.: if you opened Microsoft Word a few times, you should see a log file named winword.lgc in there.  If not, open and close Word again, then check again.  In my experience, most programs get logged after only two uses or three at the most.

3. Once you logged all your preferred programs, simply run defrag.

The result will be that only those programs you chose will be specially optimized for faster loading.

Customize in the Registry

You can also edit the way applog behaves with a little registry editing at this key:

HKEY_LOCAL_MACHINE \Software \Microsoft \Windows \CurrentVersion \Applets \Defrag \AppStartParams

The following DWORD values can be created at this key:

1. MinLogSize - whatever decimal number you enter here represents bytes. i.e. 1000, the default, would ignore all log files less than 1000 bytes in size. You might want to make that higher as very small programs such as notepad, calcualtor, etc. do not really benefit much from special optimization.

2. MaxNoUseDays - the number you enter here determines how old the log files can be before being ignored.  i.e.:  a decimal setting of 90, the default, would ignore all log files older than 90 days.  You might want to make this one lower.

3. MaxApps - the number you enter here represents the maximum number of programs to optimize.  i.e.: 50 would optimize not more than the 50 files.

You can also create a STRING value named ExcludeFiles where you can list which files you do not wish to optmize.

Personally, I do not bother with the registry customizing. I simply delete the AppLog folder and use the manual app logging method.

Disable Application Logging

If you prefer not to have app logging take place at all, you can disable Task Monitor. Click Start>Run, type MSCONFIG and under the Startup tab, remove the checkmark from TaskMonitor. Reboot for the change to take effect. You may or may not notice improved performance from the fact that you now have one less program loading at startup and running in the background.

Disable Defrag From Using AppLog

You can also disable defrag from using the logging by creating a Dword value named UseProfile at the same key used for customizing applog:
HKEY_LOCAL_MACHINE \Software \Microsoft \Windows \CurrentVersion \Applets \Defrag \AppStartParams

A setting of 0 disables. A setting of 1 enables.
Note that you need to keep TaskMonitor running for this and that the app logging will still take place.