W have a home wireless network. 3 PCs with Windows Home XP and ONE
with Windows XP Professional. I can see all 4 PCs in the network. But
the Widows XP Pc does not allow other computer to assecc its "shared
foldres". How can I fix this problem?

In order to access files on another win XP computer you would need to
have a local account, simply create a user name and password if
desired, Also you will need to put all computer on the same network,
check the IP address of all computer an make certain their IP address
starts with the same number X.X.X.anynumber The first three sets
should be the same, if not that is a whole diffrent ball game. to
check IP address click Start > Run> type cmd press enter > on black
screen type ipconfig , this will display IP address. If they are on
the same network make certain they are on the same windows domain.
Right click on My Computer click on properties > click on computer
name > Each computer should have a diffrent name(noSpaceInName) the
workgroup should be the same. Use the Change and the Network ID wizard
to configure this information. - This was way more the $5 but it's a
holiday, Merry Christmas and a Happy New Year

The problems you have seems to be connected with the rights of users
to connect to your Windows XP Machine. To check them out on your
Windows XP Professional machine click start-settings-Control
panel-administrative tools-local security policy-local policy-security
options. Here you will find a list of policies and security settings.
The ones you are interested in are:
Accounts: Guest Account Status - must be enabled  and
Network Access: Sharing and security model for local accounts - must
be set to guest only
Then you will have to check the sharing permissions to your folders -
be sure to have simple file sharing enabled.
Another more secure option is to enable shares per users , add all
users with their passwords in the network as users on the Windows XP
Pro and change the Network Access option to Classic - Local users
authenticate as themselves. This one is more complicated.
Hope you can make this one out!

1)Right Click on your "local area connection">Properties>Security &
disable the firewall by uncheck the checkbox.
2)Got Control Panle>Administrative Tools> Local Security Policy>Expand
Local Policies>Click on User Rights Assignment:Double Click on access
this computer from the network>mak esure everyone is already there is
not add everyone
3)Double click on "Deny logon locally" If here you find guest account
then remove it
4)Double click on "logon locally" .here you Add everyone account
5)Share any Drive or Folder.While accessing it from another Pc if you
get promt for username & password put XP Proff PC's username Password.
This will solve your Problem