Ensure you reference your service manual before carrying out upgrades:
The most recommended upgrade for this system is a Solid State Drive, here is my affiliate link to Crucial here. If purchasing a SSD or Memory Upgrade please use these links as I will get a tiny bit of commission which will help fund my guides.
SSD Drive Upgrade
This system supports 2 GB of RAM (2×1 GB Modules) unofficially 4 GB of RAM (2×2 GB) modules work in this system but the system maxes out at 3.25 GB of RAM. This can also be purchased using the affiliate link above.
Media Direct should be installed before the Operating System in order for the Media Direct Button to function correctly.
Not all of these systems are 64 Bit capable. A 64 Bit Processor such as an Intel T7200, T7400 or T7600 is required for 64 Bit Windows 7. Note the system maxes out at 3.25 GB of RAM so there is in any case little advantage of installing 64 Bit Windows 0n this model. This configuration works with 64 Bit Windows 10 but it is on the edge of the system requirements, should Microsoft slightly up the system requirements for 64 Bit Windows 10 later down the line, this system will likely fail to meet the minimum system requirements and therefore 32 Bit Windows 10 is recommended on this model.
It is recommended to install Windows 10 on this system see Windows OEM FAQs and Downloads. The Windows Vista OEM or Windows XP Product Key won't be compatible with Windows 10 Installation Media however you can run Windows 10 Unlicensed. Windows 10 will have most of the system drivers required inbuilt however you can install the Windows 7 Drivers if you have any unknown Devices in the Device Manager.
Drivers and Downloads for Windows 7
System Utilities (Windows 7 Only)
Chipset (Windows 7)
Video (Windows 7 Only)
Dell Wireless Cards
Audio (Windows 7 Only)
Install the Registry Edit and then the Audio Driver.
Add the entries to your registry before installing the Audio Driver.