diffence between windows 7 ultimate & professional

dear sir
what is the diffrent between windows 7 ultimet & profetional
and which is the best of optreting systems

Yes, the best version is the one that fits your needs and budget. We aren't able to tell you that, as it is a decision only you are qualified to make.

The difference between the two is Ultimate has BitLocker Drive Encryption and additional language packs. Otherwise, they are pretty much the same. Although I didn't feel I needed either one of those, I went ahead and sprung for Ultimate since it was only $20 more (only 7.5% higher than Pro) and, in the past, I've often later wished I had gotten a better version after buying a lower version and decided not to play that game again.

Only you can decide which is better, based on your own needs.

This article explains in detail the differences between the different editions of Windows 7:
Windows 7 editions - Wikipedia, the free encyclopedia

In terms of features the Ultimate edition is best, but it also costs more. The question is whether or not the added features are worth the added cost, a question only you can answer.

Dude said:

Yes and also the ram amount you can use changes up to pro, here is a snip from ms

The RAM limit is the same for Pro and Ultimate, which are the two the OP was comparing.

Lady Fitzgerald said:

The RAM limit is the same for Pro and Ultimate, which are the two the OP was comparing.

I'd also think if the OP had anything close to 192 GB of memory, he/she would already be aware of any OS limitations. I can't even wrap my head around 192 GB of memory.

As already stated, the difference between the two is the number of features which is not many at all, and there are no performance differences between the two editions. It will depend upon your needs and budget.

Home Premium contains suffice features for most people.