Yellow exclamation mark

Did you install the Desktop System Software as the very first driver installed after loading Windows?

Did you install the chipset driver? It should have been the very next driver installed after the Desktop System Software.

And sounds like you also didn't install the video driver for the ATI x300SE card. It should have been installed right after the chipset driver. And even if you did install the video drive, if you didn't install the chipset driver first, the video driver might not work.

EDIT: Natakuc types faster than I do. :emotion-2:

Windows XP has reaches End of Life as of April 2014 and should no longer be used. This system will run Windows 7, 8.1, 10 32 Bit providing you have 2 GB of Ram. You may be able to run Windows 7, 8.1, 10 64 Bit depending on the Processor. See here for drivers

http://dellwindowsreinstallationguide.com/driver-sets/dimension-desktops/

See here for A Clean Install of Windows which will take you through the install of Windows XP, Vista, 7, 8.1 and 10:

http://dellwindowsreinstallationguide.com/a-clean-install-of-windows/

If sticking with Windows XP which is highly unrecommended apply the older version of  the WSUS offline update and install the system drivers in the correct order. Keep the system offline. If you get stuck on driver install provide the hardware IDs:

http://dellwindowsreinstallationguide.com/downloading-drivers-checking-hardware-ids-and-downloading-and-installing-dell-system-drivers-in-the-correct-order/checking-hardware-ids-in-the-device-manager/

Following the advice given by RoHe

I have attempted to re install Windows XP again from scratch and installed the drivers (found by clinking on the links given) and in the order given .

The first was R121089 Dell System Software (which seems to do nothing)

Second R114566 Dell Chipset driver (again nothing)

Third q1vdo25us13 for the graphics card --this will not install at all I assume because the chipset driver is not correct

I still get errors for

Ethernet Controller

PCI Device

RTL81287B_WAN_adapter

Video Controller

Video Controller (VGA Compatible)

I assume I do not have the correct drivers ?????

Following the advice given by RoHe

I have attempted to re install Windows XP again from scratch and installed the drivers in the order given .

The first was R121089 Dell System Software (which seems to do nothing)

Second R114566 Dell Chipset driver (again nothing)

Third  q1vdo25us13 for the graphics card --this will not install at all I assume because the chipset driver is not correct

I still get errors for

Ethernet Controller

PCI Device

RTL81287B_WAN_adapter

Video Controller

Video Controller (VGA Compatible)

I assume I do not have the correct drivers ?????

Desktop System Software does nothing visible to the user. It just installs itself and you'll never see anything.

When you downloaded the chipset, it may (or not) have automatically unzipped itself, and may (or not) have automatically installed itself. If you didn't see any activity, it's possible all it did was unzip. It should have told you the name of the folder where it was putting the unzipped files, but you have to watch for it and not just click OK without paying attention.

After the chipset is unzipped, you have to go to the folder that was created and double-click on the setup.exe file to install the chipset driver. Then reboot and continue with the other drivers.

Without chipset, the other drivers might not install.

Are you sure you got the correct video driver file for your video card?

Yes

After downloading the chip set file it unzipped itself into its own folder and then run the setup program > I rebooted and have the exclamation marks. Do I have the correct chip set driver ??

What version and service pack of XP did you install? Did you install XP, with XP+SP2 or XP+SP3?

You will have the yellow ! in Device Manager for video card, network adaptor etc until after you install the correct driver for each one of those items.

Go here and be sure to change the OS setting at the top to XP before downloading any drivers. It defaults to Vista as the OS.

And just to be clear, you have the 5150, and not the 5150c which may have different drivers...

First patch your Windows XP Installation to Service Pack 3 with all XP Updates up till April 2014 using the WSUS Offline Update:

http://dellwindowsreinstallationguide.com/wsus-offline-update/

Then install the last version of XP Dell System Software:

http://downloads.dell.com/utility/Dell_System-Software_A06_R288017.exe

Then get the last Windows XP Intel Chipset Installation Utility:

https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=22153

For the unknown devices please provide the hardware IDs:

http://dellwindowsreinstallationguide.com/downloading-drivers-checking-hardware-ids-and-downloading-and-installing-dell-system-drivers-in-the-correct-order/checking-hardware-ids-in-the-device-manager/

Trying to install Windows XP Professional with service pack 2

The chip set  driver that I used is R140595 (Software utility 8.1.1.1010   A01   release date Aug 2013)

When I click on the yellow items at fault and try to update the drivers by searching to the extracted folder it states cannot find software on computer

Not sure if it is a 5150 or 5150c

I have download the latest Dell software and on running it has found new hardware ie Audio ---so now have

Audio

Ethernet

RTL8187B_WLAN_Adaptor

Video controller

Video controller (VGA compatible)

all with yellow exclamation marks

Following your instruction and running  the chip set file NF_allOS_9.4.0.1027.exe I get an error box 

"This computer does not meet the minimum requirements for installing the software -Setup will exit"

When I try to look for the ID ofrthe devices

1e Device manager/ other devices /properties there is just a single tab with a heading of GENERAL  with yellow exclamation mark

Under properties (of each of the other specific devices )

Audio & WLAN adaptor 

have 2 tabs GENERAL &DRIVER-

whilst the remaining  Ethernet- Wideo Controllers have a third tab of RESOURCES

There is no indication under any of the tabs as to their ID

The devices are typically identified by going into the Windows' Device Manager > Properties > Device > "Driver" and "Details" tabs.  I have been doing a good number of these after starting a new job a few months ago.  On the "Details" tab there is a "Property" drop-down list and you can select "Hardware Ids" from the list.  Look for a "VEN" (Vendor) and "DEV" (Device) identification and know that these details can be cross-referenced online at multiple sources (the one I use, though not an endorsement is:  pcidatabase.com )

Here is an example of a modern, vendor-specific (VEN / DEV) device:

"Intel(R) 82579LM Gigabit Network Connection", Driver version:  "12.2.45.0, dated: "10/31/2012".

If you download a version of a Driver from DELL's website and it is "A04", it is possible this specific Driver only worked with a later model (version, or edition) of the device.  You may want to try downloading and installing the "A02" version and see if that works for the specific device on the system in question.  I encountered this specific issue with a Intel network card; the 14 Mb more recent Driver did not work, but the 13 Mb slightly older Driver worked perfectly well.

If you find "VID" and "PID" descriptions in the Details, know that these are older descriptions and may mean the Drivers for those devices should be the Microsoft "generic" Drivers (vintage 2006) and that you may or may not be able to source a more recent Driver for the device.  If a product line was discontinued by the original manufacturer, well, that is what it is...  Time for a replacement device.

Here is an example of a Microsoft VID / PID device:

"USB Input Device", Driver version: "6.1.7601.18199", dated: "6/21/2006".

There is also a "Devcon" utility from Microsoft that will allow you to query all the devices on a system and list the output (results) of that query on the screen.  If you were to capture this information to a .TXT plain-text / Notepad file or .CSV (Comma Separated Values) file, then you could format the text and print out a nice copy of it for reference purposes.  This simply allows you to gather many details on all the devices quickly, if you are somewhat comfortable working with a Command Line prompt.  support.microsoft.com/kb/311272

Restoring what might be called "antiques" by today's standards is a specialized craft and I wish you all the luck with it.

Trouble is under Device manager/Properties/Driver /Driver details there is no information regarding the ID of the device as error box states "no driver files are required or have loaded for this device "  ???

I think the problem is loading the correct chip set file .

Hardware IDs are present whether or not the driver is installed or not, you just need to go to the right tab and then select hardware IDs. See here:

http://dellwindowsreinstallationguide.com/downloading-drivers-checking-hardware-ids-and-downloading-and-installing-dell-system-drivers-in-the-correct-order/

I have looked at every tab and none have a "details" tab

Just three tabs ,General ,Driver, or resources,

I assume the correct chip set  driver is for the devices built into the motherboard ?.

The motherboard is OWG261