Floppy Drive not working properly

Hello Everyone.
J'm facing a serious problem with my Floppy Drive.
The thing is that when j try to copy something to a floppy disk j get a lot of Blue screen's of death, which say:
"Disk write Error"
"Unable to write to the disk in drive A:"
"Data or files may be lost."

Somethimes j receive and windows error messages like:
"Cannot Copy"
"The disk is write protected."
"Remove the write-protection or use another disk."

Says about the write protection but the disk is not write protecded at all???
J tried 15 diferenet floppy disks like "Verbatim", "Sony", "Basf" and in every case it's the same thing, errors all the way. J tried these floppy disks on other PC and they work fine.
J tried to clean the Floppy Drive but it didn't help at all, j tried to change the power cable, and the FDD cable, but still the same thing???
At last j bought a new NEC Floppy Drive and j thought that my misery is over, BUT STILL THE SAME ERRORS AND BSOD'S.
Next j tried to re-install Win98-no good, then tried with Win98SE-no good, and at last with Win2000Pro-no good.
PLEASE, PLEASE POST SOME ANSWERS BECAUSE WHATEVER J DO IT'S NO GOOD, IF SOMEONE CAN HELP HE'S WELCOMED. J'M DESPERATE.

PS:MY MASHINE>>> PII300Cel A/ 160MB SDRAM/QUANTUM FB. 5.1 GB. HDD/ SB CREATIVE AWE 64 GOLD/ MB PC CHIPS M715 (i440 EX/LX chipset>> know it's old)/ PSU 250W. Never tried, but is it possible that it might be the PSU ???

According to the repair manuals I have, considering everything you've tried to solve the situation and using a process of elimination, it points to a bad floppy controller on the motherboard. Solution is to replace the motherboard.

You never know what you can do until you try.