The page dedicated to the Family Pack now reads: "Thank you for your interest in Windows 7. The Windows 7 Family Pack offer has ended."
The special offer, which debuted shortly before the October 22 retail launch of Windows 7, let buyers upgrade as many as three PCs from Windows XP or Vista to Windows 7 Home Premium.
The $149.99 (£91) price of the Family Pack represented a savings of $210 (£128) over three separate copies of Windows 7 Home Premium Upgrade.
When it announced Family Pack, Microsoft said that the deal would run only while supplies lasted, but declined to specify how many copies it would push into the market or when it would end.
Although blogger Paul Thurrott first noted the demise of Family Pack last Friday, searches of search engine caches showed that Microsoft pulled the edition as early as December 1, while users reported online that they had had trouble finding the discounted upgrade the week before.
"As of 11-26-09, the Microsoft Store does not offer the Family Pack," said a user identified as 'Jen' in messages on About.com.
"Their website doesn't have it and I also called and spoke with a rep who confirmed this."
On December 1, someone tagged as 'Mark A' echoed Jen's comment.
"Yesterday [Microsoft's site] linked me stores around my area that were suppose to sale [sic] it. However, several trips to local outlets was futile. I then called the Microsoft Store and they claimed they had been out of stock for past 2 weeks and can't sale [sic] it."
The sudden disappearance of Family Pack raised hackles.
"[I] am frustrated as I had planned on picking up the Family Pack in December. As others have pointed out, there was no warning that the deal was about to expire," said 'TonyB' on the same Answer.com thread.
Several sellers affiliated with Amazon.com still listed the Family Pack but had marked up the price between 70 and 90 percent, to between $255 and $285 (£137 and £175).
Several prominent bloggers have blasted Microsoft for pulling Family Pack. ZDNet's Ed Bott, for example, called it a "dumb move" in a post to Twitter last week and "stupid and short-sighted" in a later entry on his Windows Expertise blog.
BetaNews' Joe Wilcox, meanwhile, said, "I've got a new spelling for 'Scrooge.' M-i-c-r-o-s-o-f-t," in a post.
As of today, the Windows 7 Family pack was still available in the UK for the RRP of £149.99.
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See also: Windows 7 upgrade survival guide