By Fiona Roberts
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Ready for our close-up: Rita and Frank beam into their new Mac computer as they prepare to take a photo to send to their friends for his 84th birthday
Sometimes computers can fox even the most technologically minded - whatever their age.
So spare a thought for Rita and Frank, whose adorable struggle to take a birthday photo with their new Mac has turned them into inadvertent internet stars.
The couple were trying to take the picture to send to their friends for Frank's 84th birthday, but as Rita listened in vain for a traditional camera 'click' they ended up filming a video instead.
Now the hilarious tape has gone viral on YouTube, where it has been watched by more than 435,000 users so far.
It opens with the couple beaming into the camera - Rita in red lipstick, Frank holding an enormous birthday cake - for about five seconds before Rita realises something isn't quite right.
She says: 'I don't hear it clicking, do you? Do you hear it clicking?'
Then Rita dons her reading glasses to work out the complexities of Mac's PhotoBooth program.
Did you hear a click? Rita and Frank look puzzled as the photo fails to appear...
...Then Frank puts the birthday cake down as his wife attempts to figure out what's gone wrong, as all the while the video camera continues to run
At last she thinks she's solved the problem, and begins a countdown as the couple start beaming again - until: 'Did you hear a click? Did you hear a click?'
Frank answers 'no', then gives up and puts the cake down as his wife once again tries to 'practise'.
The 1.12 minute video ends with an increasingly dubious-looking Frank peering over his wife's shoulder as she tries in vain to take a still photo.
It seems they never got the picture they wanted - but despite their limited grasp of technology, they still managed to turn themselves into internet stars.