I am having a problem with a small home network.

It consists of a Windows XP PRO PC, a Dell Windows XP Pro Laptop (LT) and a Sony Vaio Windows XP Home LT.

There is a wireless router that doubles as a modem and and network connector.  The laptops are wireless but the PC is cable.

The sony laptop can connect to the network and get the internet but cannot share files or printers, all the settings are correct but someone had aprently changed something in the registry that disabled file sharing, I cannot find this piece of code and cannot find a solution for windows XP only 98, if domeone knows anything to help please suggest it here.Do you have the firewall turned on? What about if you choose the folder you want to share, right click and choose Sharing and fill out the details?Uninstall and reinstall FILESHARING from the Networks applet.I have tried all of that, it's somewhere in the windows registry i'm afraid.There are literally thousands of entries within the registry that refer to networking and filesharing so much more info would be needed.
I would have THOUGHT however that an uninstall/reinstall would have fixed things.
Are you certain that a software firewall isn't blocking it or perhaps an ENTRY via the Group Policy Editor or similar?When i have searched for the problem on the web the answers have led me down a trail of folders within the registry but this folder does not exist on XP, the code is called "nofilesharingcontrol" but i cannot find this in the registry.

http://www.winguides.com/registry/display.php/189The following areas are worth looking at for anything untoward:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
Policies\Explorer

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
Policies\System

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
Policies\Network

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\
I have checked those areas (thanks for the ideas) the only folder in policies is explorer, the is no network or system folder in there, and can find nothing in the the internet zones.Who is this someone who apparently changed something in the registry? Doesn't he/she know what was changed? Didn't he/she make a backup before changing it?
Is there a viable System Restore point available?Unfortunatly this person thinks it's fun to mess about, but no back-up was made and no resore point past Jan 2006 and this was done early last year aparently, is the only way back a clean Windows XP re-boot? because thats what i'm trying to avoid but seems to be the only possible solution.You have only yourself to blame if you let people near your systems who "think it's fun to mess about"!
If I cut the brake pipes on your car because "it was fun to mess about" what would you think of that whilst laying in your hospital bed?

Reinstall, fully secure the OS and don't let anyone else anywhere near it unless they have accounts set up in such a way that it's not possible to do any damage.I'm not trying to back out of this, you see the laptop wasn't mine, nor is it mine now, I had nothing to do with it, I was just trying to fix it.  But hey ho the joys of computers!I do tend to lose my rag a little when users appear to display such a cavalier attitude toward security. I've seen many tears shed over frauds committed (And far worse) after users allowed others to mess about.
There is one case on these very boards now where an RCT is involved. That person could well be running a spambot or worse, a kiddie porn FXP. It may well be without his knowledge, but will the authorities believe that?