I’m glad to see that you got it working!
Have fun! 
ok now i get the previous problem again
it worked the first time but a minute ago i tried it again and this time it said scope disconnected
then it said
scope will now be calibrated:
0% error all over again
i tried that “trick” again: replace that bit file, delete the PCSGU250.INI and the PCGEN250.INI
but the problem occured again
so i will buy that USB station with power adapter and see how that goes. 
Indeed, it seems that there is not enough “power” in the USB of this PC.
After purchasing the USB HUB with own power you may try to run the program with the original .BIT file.
You get the original file back by reinstalling the PCLAB200LT program.
To calibrate the scope you may either delete the PCSGU250.INI file before running the program or use the Options/Calibrate menu option.
k thanks for the help hope it works with the USB hub.
had the same problem.
I have window 7. calibration doesn’t go up from 0%.
I tried calibrating with XP VMware. same problem.
i checked the driver files.
It looks as if it prefers Windows NT.
I tried running PClab2000lt.exe in “Windows NT” compatibility mode.
It works now like a charm. You should give it a try.
Just got the same problem with new PCSGU250 connected to Fujitsu-Siemens Amilo notebook.
PcLab2000LT - v. 1.06.
Running XP SP3 tried both drivers (downloaded from your site) with zero result - no light on the device and perpetual calibrating with 0%.
!!! - Couldn’t access the file “vel255.diinoweb.com/files/pcgu250_bit.zip” - this address brings me to diino.com start page (?!)
!!! - I can’t localize PCSGU250.INI - the Search procedure ends with no result.
Please help!
Here’s a new link to download the pcgu250_bit.zip: box.net/shared/qv5binvvt7
You may try with it as described in the previous post.
[quote]I can’t localize PCSGU250.INI - the Search procedure ends with no result.[/quote]It seems there is no PCSGU250.INI. The reason to this is that the program is not closed properly.
The situation with PCSGU250 didn’t change with me.
What I did:
A. I started using other USB slot on my notebook.
I deinstalled PCLab2000LT and drivers. I cleaned the registry.
I installed again PCLab2000LT and launched it in Windows NT compatibility mode. Demo mode works.
I connected PCSGU250 and installed driver. I launched PCLab2000LT. While connected to PCSGU250 PCLab2000LT (no lights on the device) asked for calibration. Then - perpetual calibration with 0%.
B. I repeated A with PCSGU250 connected trough USB hub with separate power supply. The same result - 0%.
C. I repeated B using downloaded PCSGU250.BIT you recommended (for less current). The same result - 0%.
In all the cases while PCLab2000LT is trying to calibrate the CPU load is 50% (by Windows TaskManager).
I need your advice what to do next. 
To test the PCSGU250 is not defective you can now download the PCSGU250.INI file from this link:
box.net/shared/dhb7o8ncd5
Replace the PCSGU250.INI with this file in the folder C:\Documents and Settings[i]username[/i]\Local Settings\Application Data\Velleman\PCSGU250.
This file contains the calibration results and there will be no calibration.
The PCSGU250 should start and run without calibration.