Windows 7 win7 and xp problem

Yes and thank you.
You have among many (too many) startup items running;
Avast remove using this Link Removed
AVG remove using this Link Removed (get the correct version for your install should be 32 bit according to your attachment)
Comodo use the programs own uninstaller utility or the programs and features applet in the control panel or google and see what's out there Link Removed
and
Zone Alarm use the programs own uninstaller utility or the programs and features applet in the control panel or google and see what's out there.
You may have to resort to a third party software uninstaller like Link Removed or Download Revo Uninstaller Freeware - Free and Full Download - Uninstall software, remove programs, solve uninstall problems and even then you may have to follow up with some registry edits.
Replace these products with the built in Windows firewall product and Link Removed due to 404 Error
Let us know how you're progressing.
Regards
Randy

That took a bit of doing, but I think I've managed it all.I can't see zone alarm because I think I uninstalled that earlier. I replaced them with as you suggest, windows firewall and security essentials, I have read that I need more than the windows firewall on XP is that right? I used revo uninstaller for some of this and looking through the list of programs it comes up with it's got microsoft.net framework 3 times and visual++ 4 times, is that right? Anyway,I still get the same message on the desktop i.e. windows can't access HOMENETWORK.

OK.
Attach another (most recent) copy of your System Information Utility report, as you did previously. I'll take a look and see what if anything remains.
Additionally double check and make sure that both machines are members of the same workgroup
Join or create a workgroup
Link Removed

ok I think this is the file. I have checked computer names and if members of same workgroup,which I have called HOME. I believe they are although I'm not quite clear re Windows7 as it there is HOMEGROUP which can't work with XP,I believe.

Yes, thanks again.
Two services still running
Click the start orb and type
services.msc
hit enter
scroll as needed to find
Bonjour Service
double click it
change the start up type to disable and click the stop button.
and
TrueVector Internet Monitor
same deal double click it and set the startup type to disable and click the stop button.
Find (do a search for
vsdatant.sys probably in C:\Windows\System32\Drivers
right click and rename to vsdatant.OLD
reboot your computer.
If problem persists read these two articles
Link Removed (especially for home edition of XP)
Error message when you try to access a Windows XP-based network computer: "You might not have permission to use this network resource"

Glad to hear that you were able to resolve your problem. Thanks for posting back and updating your threat with that information.
As far as the Outlook Express message, it would likely come from a startup program so check by typing
msconfig
into the search box and hitting enter
select the startup tab and look for applications that are running at startup that may be associated with this message, either outlook express or another program that for some reason thinks Outlook Express is your default mail program.

As far as a personal software firewall product, I will defer to others who might have more personal experience than me regarding the topic.
Frankly I have never bothered, being behind a network address translation device as well as using the built-in firewall product to block or allow services or software has always proved satisfactory for me, and generally speaking barring any malicious software, outbound connections are generally intentional and required by many software products in order to work properly (like Skype), you can check or uncheck them under the advanced tab->settings (button)->Exeptions tab, in the properties of your network adapter.

I would expect that both Zone Alarm as well as Comodo are fine products but require some sophistication when it comes to tweaking settings and understanding some of the finer points of configuring the software properly to support what you intend.
The only software firewall product I have any experience with is ISA (Microsoft's Internet Security and Acceleration Server, very old by todays standards) which runs atop their server offerings. Outside of that, mostly hardware appliances like Cisco PIX boxes which are generally rather expensive.
Some of the newer routers / appliances that are provided by some ISPs or can be purchased and added to your network have some pretty sophisticated firewall offerings as well as SPI (stateful packet inspection) that don't burden you computer with such tasks.