The first iPAQ Pocket PC was the H3600 series, released in 2000.[1] It ran Microsoft's Pocket PC 2000 operating system, and featured a 240 x 320 pixel 4096-color LCD, 32 MB of RAM, and 16 MB of ROM.[2][3] Compaq released a similarly-designed H3100 series Pocket PC in January, 2001.[4] It was a lower-priced model[5] with a 15-greyscale monochrome LCD, 16 MB of RAM, and a dark grey D-pad instead of the chrome D-pad of its predecessor.[6][3] The H3600 series was succeeded by the H3800 and H3900 series, which retained the same form factor, but had a different button layout.

Soon after HP's merger with Compaq in 2002, HP discontinued its Jornada line of Microsoft Windows powered Pocket PCs, and continued the iPAQ line that started under Compaq.

In June 2003, HP retired the h3xxx line of iPAQs and introduced the h1xxx line of iPAQs targeted at price conscious buyers, the h2xxx consumer line, and the h5xxx line, targeted at business customers. They were sold pre-installed with the Windows Mobile for Pocket PC 2003 Operating System. The h63xx series of iPAQs running the Phone Edition of Windows Mobile 2003, the hx47xx series and the rz17xx series, both running the Second Edition of Windows Mobile 2003 were introduced in August 2004.

In August 2004, HP released the rz17xx and rx3xxx series of Mobile Media Companions. These devices were aimed at consumers, rather than the traditional corporate audience. Emphasis was placed on media features, like NEVO TV Remote and Mobile Media. They ran on Windows Mobile 2003SE.

In February 2005, the iPAQ Mobile Messenger hw6500 series was introduced to selected media at the 3GSM conference in Cannes, France. It was replaced a year later by the hw6900 series, running on Windows Mobile 5.

In 2007, the iPAQ rx4000 Mobile Media Companion PDA/media devices and rx5000 Travel Companion PDA/GPS devices were released. Both series of iPAQs work on the Windows Mobile 5 Operating System (WM5), as do the hx2000 and hw6900 series. The first HP Windows Mobile 6 device, the iPAQ 500 Series Voice Messenger, with the Windows Mobile 6 Standard Operating System (WM6), and numeric pad, was released in the same year.

The entire iPAQ line was completely revamped by the introduction of five new iPAQ series to complement the introduction of the iPAQ 500 Series Voice Messenger earlier in the year. The models announced were the 100 Series Classic Handheld, the 200 Series Enterprise Handheld, the 300 Series Travel Companion, the 600 Series Business Navigator and the 900 Series Business Messenger. The 100 and 200 Series are regular touchscreen PDAs without phone functionality running WM6. The 300 Series Travel Companion is not a PDA; marketed as a Personal Navigation Device, it is a handheld GPS unit operating on the Windows CE 5.0 core Operating System with a custom user interface. The 600 and 900 series are phones with integrated GPS and 3G capabilities, running the WM6 Professional. The 600 series possesses a numeric pad and the 900 series features a full QWERTY keyboard.