I spent one whole day for assembling it, and it has worked....and is working since last 2~3 years. There are a lot many jumpers on the General Purpose Board....looks very very creepy....but it still works fine.

And I had lots of problems in starting this programmer in XP, so I had partitioned the disk for Win98 and it works fine. So my PC has 2 partitions: Win98 for MCS51, WinXP for Microchip...and am quite satisfied the way they are working for the last 1 year.

You have not posted the link to this programmer.
Are you talking about "ISP Flash Microcontroller Programmer Ver 3.0a" ? I had built this on GP Board, and the values of capacitors and resistors is very important; put them as they are mentioned.

Look at the circuit diagram again, do not take the component values for granted, put them as they are mentioned in the circuit diagram...Do not cut corners. See that you have configured the Port correctly. I mean: set the Port in software, to the port where you have connected the hardware.

And one more important point. They do not work on USB-Serial convertors or USB-Parallel convertors.

Bye,
from Kiran V Sutar, Mumbai, INDIA.