HP Compaq DX2420 Microtower Computer (Hardware Upgrades, Windows Vista Installation & Review)

This blog post is about HP Compaq DX2420 microtower computer hardware upgrades, improving computer performance, Microsoft Windows Vista installation, a review and more!

November 2019: This blog post is outdated and I recommend you read my updated blog post here.

HP Compaq DX2420 Microtower Computer

14th July 2018 update: Since publishing this blog post I’ve written the following:

HP Compaq dx2420 Microtower Computer / MS-7525 Motherboard Bios Flash

HP Compaq dx2420 Microtower Computer Dual-Core to Core 2 Duo CPU Upgrade

Disclaimer: My assessments below are based on two computers purchased second-hand and then upgraded. If there were any upgrades or changes in hardware before I purchased, I am not aware of them, so please take this into consideration whilst reading this blog post.


This is an old business computer PC that might have originally been released in 2009! I’ve been using this model since 2013 and entering 2015, I’m still happy with the technology as it meets my current requirements still!

I’ve owned Compaq machines before and now under HP, the brand and build quality shows in this workhorse tower computer. After buying one of these machines, I purchased two different computers by other manufacturers for other uses, but was less than happy with them, and since then I have replaced one of those machines with a second DX2420, which means I now use two of the same model!

If you are patient and fortunate with the listings, you might be able to buy a second-hand DX2420 for around £35 – £45 GBP on eBay in the UK.

I use one of the computers for personal use and the other for work, taking over responsibilities from my old Dell Latitude D620 laptop. I’ll go into more detail below on how I use them.

Using the HP Compaq DX2420 for work.

Even in early 2015, this computer running Vista and Norton Internet Security copes well with my administration tasks and many other applications. I happen to be a Paint Shop Pro 9 addict, and this old program runs smoothly, as well as modern incarnations of LibreOffice, GiMP and Thunderbird.

The specification I’m using:

  • 4GB DDR2 PC-5300 240-pin RAM (2GB in each slot).
  • Intel Pentium E5300 (Dual-Core) Socket 775 LGA CPU @ 2.60GHz
  • Microsoft Windows Vista 32-Bit (which means only 3.5GB of ram is being used).
  • 250GB sata hard drive.
  • ATI Radeon HD 5450 PCI Express (not supplied with computer) with 1GB DDR3 Ram

Unlike my gaming system below, the network connectivity is being provided by the RJ45 port (ethernet), linked to an old WRT54g wireless router. The computer is reasonably quiet, still using the original 300w PSU supplied with the computer. It has USB, speaker and microphone ports at the front and rear of the computer.

The ram in this computer at the time of purchase was 2GB PC2-5300 DDR2 with a 1GB being in both supplied ram slots. Recently I upgraded this to 4GB for only £18 on eBay, which was a good deal and helps the computer cope with the Mozilla Firefox browser, its add-ons and some other software I use.

Radeon HD 5450 Graphics Card Box

The graphics card was an additional purchase, and is quiet as it doesn’t have a fan and is a reasonable purchase for a cheap old computer. I’ve got two monitors on my desk and use both the VGA and DVI connectors on the PCI-Express graphics card at the same time.

Using the computer for gaming!

This computer isn’t intended for high performance gaming, but there are some fantastic games both old and new that run fine with a graphics card upgrade.

Inside HP Compaq DX2420 Computer

I’ve put this computer into my lounge area to use as a Steam box running Microsoft Windows Vista! I purchase games via Bundles Stars, Humble Bundle and Steam and make sure they are activated in Steam. Two of my favourite games are Broforce and Towerfall Ascension, which looks great in full screen on my large TV screen via a HDMI port.

HP Compaq DX2420 Computer Rear

Also occasionally I will play Red Alert 3, Age of Empires II, Company of Heroes (not the sequel) and StarCraft 2 as I’m a massive RTS gaming fan, but these are not suitable for playing from a sofa!

It is important that you check the specs of any games you wish to run on the computer. I recently I discovered I couldn’t buy Planetary Annihilation as my specifications were just not good enough.

The gaming setup is:

  • Intel Pentium E5300 (Dual-Core) Socket 775 LGA CPU @ 2.60GHz
  • ATI Radeon HD 5450 PCI Express graphics card with 512MB DDR3 Ram
  • 300GB sata hard drive
  • 3GB DDR2 PC-5300 240-pin RAM (2GB in one slot and 1GB in the second!)
  • PCI wireless adapter
  • Two gamepads connected via USB extension leads
  • Small 2.4GHz Mini Wireless keyboard and mouse with a USB dongle

Small 2.4GHz Mini Wireless Keyboard and Mouse

As you will notice my hardware spec for gaming isn’t as good as my business machine, but even with the additional purchases of the graphics card, RAM, wireless adapter, gamepads and wireless keyboard and mouse (connected by a dongle), the 300w PSU is still coping! Instead of using the DVI or VGA outputs, I’m using the HDMI for both audio and visual outputs!

I know the Radeon HD 5450 is a low budget graphics card, which many gamers would overlook, but for my taste in gaming it is fine. I’ve now purchased two of these cards via eBay spending £6 and £15 each time (can’t remember if that includes P&P).

I especially like the fact that plugging the HDMI lead from the card to my television, means I can also adjust the volume of the output of my computer via my TV remote! This is possible by changing the default ‘playback device’ in Windows when using the HDMI lead.

Microsoft Windows Vista reinstallation

Both the HP computers I purchased via eBay didn’t come with an installation DVD, but had a COA label with a Vista Business Product Key. I didn’t have a HP Compaq DVD, but was able to install a clean version of Vista using another Vista installation DVD.

During activation I was worried that perhaps the license key had already been used too many items for reinstallation (I was unsure), and initially they wouldn’t activate and was advised by a message to phone, but when I selected ‘change product key’ and typed the same key in again, both were successfully activated online. Obviously others might be as fortunate as me.

Simple FAQ

Hopefully the various photos I’ve taken will help answer questions, but I’ve also supplied a basic FAQ.

Q. How many RAM slots does the HP DX2420 have?

A. There are two slots available for ram. I’ve run three different setups of RAM so far, which were: 1GB in each slot, 2GB in one slot and 2GB in both slots.

HP Compaq DX2420 Computer Ram Slots

Q. What is the maximum amount of memory (ram) that can be installed?

A. I believe it is only 4GB of ram, with a maximum spec of DDR2 PC2-6400 800Mhz 240-pin. As you will see in the two computers mentioned above, I’ve been running lower spec DDR2 ram.

Q. What operating systems are suitable for the computer?

A. I believe people have used FreeDos, Windows XP and Vista. I’ve not tried Windows 7 on it yet, but have run a linux based operating system before on the computer.

Q. Does the tower computer have inbuilt wifi (wireless)?

A. No, it only has a RJ45 ethernet connection on the motherboard, which is suitable if you are running a powerline connection or are near a RJ45 wall socket or router. In one of my computers, I’ve installed a PCI wireless adapter, which runs fine with my specific PCI-Express graphics card also installed.


This is an old computer system and thus you must factor in wear and tear and the possibility of component failure when buying a second-hand computer. I’ve experienced no issues yet and at the time of writing running Microsoft Windows Vista is fine for my needs.

A cheap investment in technology over the last couple of years. Since owning them, I’ve used them for many hours, and without complaint!

The only upgrade I would now consider is a new CPU, but in 2016 I might look to upgrade to an i3 or i5 CPU based computer system, but for now, I’m happy with this computer system.

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