I can't help you on this one Roland. A Google search doesn't find much for this model - and mostly foreign language (to me). There were only four hits on Google!

It's possible that there isn't any BIOS update available, try asking IBM again.

Why do you think you need a BIOS update? What problems are you having?

Roland,

I went to the IBM website as well and I noticed something curious.  It seems as though the lump all of their NetVista models into a single category, they call NetVista Personal Desktop Computer.    So, it looks like you need to simply page through until you find the 6645.  I didn't look through all of them, but from the looks of things, this has all of the NetVista downloads.

Also, before you begin, Please double check that number 6645.  Their seems to be a lot of NetVista model numbers, so 6445 or 6654 most likely are valid model numbers (which would be one digit off of the model you gave).   

http://www-307.ibm.com/pc/support/site.wss/product.do?subcategoryind=0&familyind=50246&brandind=11&doccategoryind=0&modelind=0&doctypeind=9&validate=true&partnumberind=0&sitestyle=lenovo&template=%2Fproductpage%2Flandingpages%2FproductPageLandingPage.vm&operatingsystemind=49980&machineind=0

If you still are having trouble locating your model, what you should do is this:
when you are booting your system, right when you see the first screen pop up, it usually has your model number AND it has your BIOS Revision Number.    This usually pops up quick and then disappears, but there is a trick that you can do, hit the "Pause-Break" key once when you see that screen and it will freeze on that screen.     Then you can write down the Model and BIOS revision Number.  Then hit Pause-Break again, and it will resume booting.   Then do a search on the IBM site for that particular BIOS Revision Number or the model number.   

That will usually lead you to the area where you can download a BIOS update that will work for your system.

Hope that helps.   

Roland,

Looks like you are going to have to keep chasing IBM to see if they can give you an answer. It's unlikely that you are going to find someone with the same model and who has managed find a solution through the forum.

What type of file is the update?   (for example, .INF file or a .EXE file)   If it is an .INF file, try right clicking on it, and choose the "Install" option. 

 Update programm it's auto-executable and create a floppy disk or an boot cd.; the file wich containing P III/1GHz has no type(.txt, .exe, .bat), it's named 068A only. As I said, if put it in the updated cd the programm says there is no update for my peocessor. Maybe somewhere it's described the list of updated to do, and even the update it's there the programm ignore it.

E-he-he, my friend, I already have an P IV/1,8 GHz, 512 Mb-DDRAM, DVD RW,and so on.
One year ago I had to buy one more pc because I had to do a lot of works. That one was
good enough regarding price/performance - only 60 $. I'll need it one more year till I'll finish
my works then I'll use it as typewriter...
It was nice to talk with you.