Comodo Firewall Pro and internet problem in XP SP2

well :: i have a desktop computer with following configuration ::

Processor Intel Pentium III
797 MHz, 384 MB RAM

Microsoft Windows XP Professional version 2002
Service Pack 2

the main softwares installed to avoid viruses and spywares etc ::: are

a-squared free 3.1
avast version 4.7 Home Edition Build Dec2007 (4.7.1098)
CCleaner v2.3.532 (without toolbar)
Comodo BOClean Anti-Malware
Comodo Firewall Pro (basic firewall installation)
Diskeeper 2008
SpyBot - Search & Destroy (without teatimer)
Spyware Blaster

Almost all windows updates and software updates already done on my computer

in the begining it works very well::: Before yesterday, it stops working and become halt ::: i forced it to shut down by pressing power button for long time ::: the next day, when i started computer, and i open internet explorer, it goes to google site but after that it loose connection ::: and after that each and every time i restarted it did the same thing ::: i checked with CD provided by my internet provider (company name: Free) and there was internet connection but internet explorer was showing the page with the message that the required page cannot be opend ::: it was as there was no connection because i tried to update antivirus and other programs and they showed the no internet connection message ::: yesterday night, i restarted computer in safemode with networking (as advised by another majorgeek) and it worked perfectly ::: there was internet connection and each and every site was opening :::: then i rerstarted the computer and same thing again ::: well today, finally, i uninstalled comodo firewall pro and activated windows own firewall and restarted the computer::: after restart, avast updated successfully, and it showed google main page but after this, it lost connection again ::: i restart the computer again and now it is working well::: there is no disconnection upto now ::::

i think that there was some firewall problem ::: as i know nothing about firewall:: how to set it or how to configure it ::: may be there were some options being unabled which should not be :::::

now i require your kind help in this regard ::: what should i do :: what kind of firewall i should install ::: if i re-install comodo firewall pro, what should i do to assure that it will not block internet connection ::::

Thanks in advance for your kind help

 

Thanks a lot ::: i will try to re-try comodo firewall pro and i will try to better understand the firewall:: if the problem exists, i will write here :::
thanks again

 

Thanks for your replies and happy new year to you also :::
well:: i re-installed commodo firewall pro in standard mode and it blocked again the internet ::: in comodo firewall pro, Firewall security level is on Train with safe mode and defence + security level is on Clean PC Mode::::
what should i do please???? should i re-installed in advanced mode or should i change something in this standard mode:::

 

well how can i clean out application data files for comodo firewall plz???

 

thanks::: well i remove n uninstall comodo firewall as u mentioned ::: then i reinstalled comodo firewal n connection is gone ::: it didnot copen any site or update ::: no connection at all::: well i willtry to see with their forum ::
thanks for ur time