HP4100C Unknown Device

I have had this problem before on different computers with the HP4100C model scanner and have never been able to solve the problem, even with the help/suggestions of HP.
Now I have the problem again and would like to know if (finally) there is a solution:
The problem:
A computer was formatted and Windows 98 (1st version) was installed (Portuguese version). The installation went on 100% ok, the machine has no IRQ conflicts and is working fine. I then installed the HP4100C software with the original CD the comes with the scanner (without the scanner connected) and the installation went on fine as well. The problem is that when I plug in the USB cable, Windows tells me that it **has** found an HP4100C scanner but **can not** find the drivers for it, asking to insert a disk. I then insert the original CD again and tell him to search in D: (and under directories like D:\PORTUGUESE\DRIVERS, etc.) but it tells me that there are no drivers there for that scanner. I've uninstalled the drivers and installed them 3 or 4 times, but the problem is always the same, so in the end it installs the scanner as an "Unknown Device...". The USB ports are working fine because the scanner **is detected**. Just in case, I've also removed and reinstalled the USB devices (USB Root, etc), but the result is still the same. A stange thing is that the scanner was previously working on this computer but it had Windows 98 preinstalled from factory. Some months ago (the last time I had this problem) I really had to give up and I sort of came to the conclusion that it was a "HP software bug" on this model. I completely stopped buying the HP4100C model but I still have to deal with the existing ones...!!!
Any solution or updated drivers (since + - 4 months ago) that can solve the problem?


Estêvão Raminhos
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Ok here are sopme solutions for you

1. Uninstall the scanner completely then reboot windows once in windows hit CTRL,ALT, DELETE and end task everything except for explorer and systray then reinstall this will ensure it is properly installed

IF windows plug and play comes up the screen that says device has been detected etc... just cancel it out.

if that does not work then try this

ISSUE: A USB-connected HP ScanJet scanner fails to work when installed, or quits working after it has previously functioned. The scanner may also appear as an unknown device under the USB category in Windows Device Manager.

SOLUTION 1: See the following for problems with specific makes and models of PCs.

IBM 300GL or IBM 300PL computers
USB ports on the 300GL/PL may experience a communication problem known as "jittering." Contact IBM to see about replacing the motherboard.

E-Machine Model 336e
Customers who have this computer have resolved their issue by replacing the E-Machine Model 336e with Model 336i. The root cause of this problem is currently unknown.

Toshiba laptops
Owners of Toshiba Techra, Infinia, and Satellite Pro laptops may experience problems connecting a USB scanner. If the normal troubleshooting steps do not resolve the problem, running the scanner on the USB port may not be possible. If the scanner has another interface option, like SCSI or Parallel, the scanner may work just fine by using that interface.

Quantex computer
Go into CMOS Setup (BIOS), Advanced Chipset, and enable the USB port and the Passive Release. You may need to contact your PC vendor or manufacturer for assistance in making these changes.

SOLUTION 2: Uninstall and reinstall the scanning software. Shut down the PC and disconnect the scanner USB interface cable and power. Re-connect the power back to the scanner, and then reconnect the USB cable. Then reboot the PC.

SOLUTION 3: If the scanner is an HP ScanJet 4100C, 5200C, 6200C or 6250C family scanner, you may need to download the USB patch. Click here , to download the patch: SJ435EN.EXE. In the Search window type in the file name: SJ435EN.EXE, then press the Search button.

SOLUTION 4: If the scanner is an HP ScanJet 6200 or 6250C or HP ScanJet 5200C, switch the scanner lamp Operation Mode from Economy/Energy Star-compliant to Fast Scan.

Open the Control Panel, open Scanners and Cameras, select Properties, and then select Lamp. Change the setting from Energy Save to Faster Scan, then select OK. Shut down the PC; disconnect and reconnect the scanner power cord. This cycles the scanner's power. Restart the PC.

SOLUTION 5: If the scanner is an HP ScanJet 6200 or 6250C or HP ScanJet 4100C scanner, verify that the file HPSJCLAS.DLL exists on the system and is 20 KB in size. If the file cannot be found, or it is larger or smaller than 20 KB, then copy the file from the Drivers directory of the HP CD-ROM to the C:\Windows\System directory on the PC.

SOLUTION 6: Right-click the My Computer icon and select Properties. Click the Device Manager tab, scroll down to Imaging Device, click the plus sign (+), and select the scanner listed. Remove the scanner with the Remove button at the bottom. Shut down the PC; unplug both the USB cable and the power cable from the scanner. With the PC off and the USB cable still disconnected, plug the scanner power cable in and let it completely power cycle before unplugging it. Power cycle the scanner at least five times this way before hooking up both cables and restarting the PC. New hardware should be found on the reboot.

SOLUTION 7: If the scanner is an HP ScanJet 5200C or HP ScanJet 4200C scanner, verify that the file HPSJVSET.DLL exists on the system and is 90.5 KB (for the 5200C) or 92.5 KB (for the 4200C). If the file cannot be found, or is the wrong size, copy the file from the HP CD-ROM to the C:\Windows\System directory on the PC.

SOLUTION 8: In Windows 98, check the Automatic Skip Driver Agent to find out if any drivers (in this case, USB drivers) are being skipped by Windows.

From the Windows desktop, choose Start, Programs, Accessories, System Tools, and then System Information.
Select Tools and then Automatic Skip Driver Agent. If any drivers are listed as skipped, check the box next to the driver, and then reboot the computer.
Check Automatic Skip Driver Agent again. If the USB drivers are still being skipped, contact the USB manufacturer for specific USB troubleshooting.


NOTE: We have seen some instances in the past where having the USB Host Controller share an IRQ with another device has caused the scanner to not be recognized by the computer. This has been especially true when sharing IRQs with ISA cards and network interface cards. Although it may or may not be a solution, we do recommend that customers investigate the possibility of having the USB Host Controller be on an IRQ alone, if only for testing purposes. This would need to be done with the manufacturer of the computer.



WARNING: Do not change any other settings in the BIOS this could cause other computer hardware not to work.

finally if none of this worked try this

From the Windows 98 Desktop click Start and then Run.
Type msconfig in the dialogue box and press enter.
Select the Startup tab and make sure there is a check mark in the box next to StillImageMonitor. If StillImageMonitor is not here skip step 5.
Exit the System Configuration Utility screen.
Restart the PC.
If StillImageMonitor is not present in the Startup tab, follow these steps:

Right-click the My Computer icon, select properties, then Device Manager.
Look for the Scanners and Cameras entry and click the plus (+) sign.
Highlight the HP ScanJet 3300C entry and click Remove saying yes to the removal warning.
Insert the HP Scanning Software CD in the CD-ROM drive then click Refresh.
Windows will install the necessary software.
Reboot the PC.    
If Brian's "suggestion" doesn't work...try this.  When the pc boots up and finds new hardware...put in the Windows 98 CD and tell it to look at D:\win98 (or the portuguese equal to that). If it still cannot find the drivers then browse on the Win98 CD to the directory where the cab files are loaded and then tell it to look. The driver files it is looking to load are in the windows 98 cab files.
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