May someone help me to solve this problem? Did I have mistake when
up-grade 9.04? Please help me.

I have open Hardware driver and got "No
proprietary drivers are in use on this system".

Now, I have been connecting internet with Ubuntu 9.04 (I have connected
internet with XP before,then restart my computer). Herewith I have
attachment file consist of lshw.

*-network DISABLED
description: Wireless interface
product: PRO/Wireless 3945ABG [Golan] Network Connection
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:02: 00.0
logical name: wmaster0
version: 02
serial: 00:1b:77:2b: ab:ab
width: 32 bits
clock: 33MHz
capabilities: cap_list logical ethernet physical wireless
configuration: broadcast=yes driver=iwl3945 latency=0 module=iwl3945
multicast=yes wireless=IEEE 802.11abg

I clipped the network section only. Your network is disabled. It looks to me
that you need a driver. You can use ndiswrapper to use a Windows driver. To do
this, you need to install ndiswrapper and ndisgtk from the repositories using
Synaptic. Once installed you run ndisgtk from your Administration menu. You need
to insert your Windows driver and then locat the .inf file on the disk. It will
load the Windows driver and make a module for you. Once done, re-boot. The other
option is to try to locate a Linux driver for your particular card.

I am not exactly a network guru. Others have more exp[ertise than I. However, I
have used ndiswrapper successfully on my netbook with some distributions.
Wireless is one of those areas where Linux needs more cooperation from OEMs.

I think, my modem is not supported by new
kernel.

Now, I'm looking for Ubuntu driver or Windows driver as your advice. In
XP, modem driver use SYS file, not INF file. So, I can not use ndisgtk .
If there is no driver, maybe I have to buy new modem or "down grade" to
8.10.

I also have other problem, when I'm connecting to internet (as usually,
I have to connect with XP first), in Network connections, the last
connection was 2 days ago, not now. Actually, I can connect, browsing,
etc (Mobile broadband connection 'Excelcomindo (XL)' active). Something
wrong with my Ubuntu 9.04.

I had the same problem. Go into your wire/wirless settings and set the SSID.
Once I did that it worked fine on my wireless network. Not sure why it didn't do
it when I updates, like it did when I went from 8.04 to 8.10.