Wireless Connected to Internet but Unable to Use Browsers

I have an Acer Ferrari 4000 (AMD Turion 64 Mobile; Technology ML-37;880 MHz 1.00 GB of RAM) running MS Windows XP Pro Version 2002 SP3 which I have just reinstalled. Everything worked smoothly but the next day I could connect to my wirekess router but nȯne of my browsers worked (Opera, Firefox, IE), even though I can - curiously enough - still use the e-mail function of Opera. Skype works fine, I can ping normally and non-browser based software updates are also no problem.

I have tried basically all of the advice that I could find around here and elsewhere; Winsockfix did the trick a previous time when I had the same problem, but not this time; netsh winsock reset catalog; netsh int ip reset reset.log... all no use.

I have the following system software installed: Avast, Spybot, Glary Utilities, HD Tune, Registry Booster 2, SpeedupmyPC 2009 and Smart Defrag...

These are my IP settings:
C:\Documents and Settings\Administrator>ipconfig /all

Windows IP Configuration
Host Name . . . . . . . . . . . . : kris
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Wireless Network Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Broadcom 802.11g Network Adapter
Physical Address. . . . . . . . . : 00-0E-9B-CA-74-FE
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.0.100
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1
DHCP Server . . . . . . . . . . . : 192.168.0.1
DNS Servers . . . . . . . . . . . : 192.168.0.1
Lease Obtained. . . . . . . . . . : Thursday, November 05, 2009 11:51:31 AM
Lease Expires . . . . . . . . . . : Thursday, November 12, 2009 11:51:31 AM
Ethernet adapter Local Area Connection:
Media State . . . . . . . . . . . : Media disconnected
Description . . . . . . . . . . . : Broadcom NetLink (TM) Gigabit Ethernet
Physical Address. . . . . . . . . : 00-C0-9F-A7-0E-EA

Getting a little desperate after two full days of tinkering and rebooting with no result... Any suggestions very much appreciated!

No more need to give a solution, after some more trial and error I solved the problem myself...!!

I disabled the Avast Web Shield 4.8-1356 and everything started working again. I haven't gotten the slightest clue why exactly this caused my browsers to stop working (my wife's computer has the exact same software installed and hasn't gotten a problem at all and I have been using the combination of Avast and Spybot for at least 1 1/2 year) but right now I'm back in business. If I re-allow that Avast provider to be active, the same thing happens again: all browser activity stalls. Go figure...
I also un-installed Spybot and replaced it with Spyware Doctor since the Teatimer was taking up too much precious CPU space.