Apple's new look operating system got off to a rocky start as users complained about difficulties downloading it.
Hailed as a new beginning for the technology giant, the iOS 7 was eagerly anticipated but tech fans complained of messages telling them: "An error occurred whilst downloading iOS 7.0".
Users took to social media such as Twitter to express their frustration at the setback as "iOS 7.0" became a trending topic.
Conor Rickards, using the handle @_cajr, opted for irony, tweeting: "Having a great time using IOS 7.0" whilst posting a picture of the error message."
"I don't understand why it won't let me download iOS 7.0," wrote Diana Ulloa (@Deeandhearts).
Others, such as @King_Julien1984, complained about messages telling them their download would take 11 hours to be completed.
Elle Lake (@lizzylake) said: "43 minutes remaining to download iOS 7.0 but now 10 minutes later there is an error,and I have to upload it again with another 2 hour wait"
@igc223 13m said: "deleted all my apps, music, and pictures and still don't have enough storage to download iOS 7.0"
Some had managed to download the system and praised it, such as Ashlyn Tracy (@MsPrettyPricey), who said "Loving the new iOS 7.0 #iPhone .get it people"
Industry observers had suggested the arrival of iOS 7, which is said to have a cleaner look than its predecessors, could go some way to silencing Apple's critics.
It was unveiled just months after Apple posted its first profit slide in a decade and drew accusations that it has failed to innovate.
British design chief Sir Jonathan Ive introduced the operating system as an ''important new direction'' when he showcased the software at Apple's annual Worldwide Developers Conference in San Francisco earlier this year.
The American company's CEO Tim Cook described it as ''the biggest change to iOS since the introduction of the iPhone''.
It has been designed to make the iPhone appear bigger, with features crafted to take advantage of the entire screen.
Text is said to appear sharper, while a ''control centre'' on the phone allows users to adjust settings with just one swipe from the bottom of the screen.
This gives instant access to functions such as airplane mode, wi-fi, bluetooth or do not disturb, and enables users to quickly pause or play a song, jump to the next track and stream music.
Meanwhile a ''notification centre'' is available from the ''lock'' screen so users can view updates with a ''simple swipe''.
Apple has also introduced an AirDrop tool to share content - which is said to be fully encrypted - with contacts nearby, and has added further updates to its cameras and its Siri feature.
The new operating system's launch this week comes just days before two new iPhones go on sale - one of which features a fingerprint scanner.
Executive Phil Schiller sent a massive cheer through the audience at the San Francisco conference in June when he told developers: ''Can't innovate any more, my arse!''