I cant find the numbers

Saw an article saying it sold around half a million, will try to find it.

Here it is, it was actually 1/4 of a million:

Sales

When the Xbox launched on November 21, 2001, the console quickly sold out in North America. In Japan, however, the console sold only 250,000 units. After its release in November 2004 Halo 2 became the best selling Xbox title worldwide, selling over 8 million copies, thanks in large part to the quality of its online multiplayer through Xbox Live. It was arguably the most popular online mutliplayer shooter on home consoles during the sixth-generation of consoles.

According to Microsoft the Xbox has sold over 24 million worldwide as of 2006.

I actually doubled the amount of units it had sold in Japan. The actuall number was 250,000

Thanks, but i was more interested in first week

Sorry about that didn't know what FW meant, will try to find it for you .

165K units between February 22 and March 31, 2002 according to Media Create is the only number I found.

EDIT:

109.663 FW Media Create, Famitsu like the others said.

Sorry about the mishap, this graph says that is sold 160k:

Here is also a graph of Xbox sales for the rest of 2002 for comparisim sake:

Xbox org: 123,929/476,000
Xbox 360: 62,135/1,650,000

These are the numbers from Famitsu/Media Create. 

While this is irrelevant to what the OP was asking, I'm pretty sure it sold around 800k in Japan by the end of production. 250k sounds unbelievable, even by Japanese Xbox standards.

Thank you, very interesting, i though X360 sold more FW than the first xbox.