It is/was like when... ，此用法常见于口语。

从语法角度看，like 的宾语实际是被省略了，具体省略了什么可以从上文信息中找到。when 只是被省略成分的一个时间从句罢了。我试着补上省略的成分：

It was like what it was when you defrag the hard drive on your computer. 

又如：

1. See everything real sharp and clear, like when I was young.  

每见事看的既清楚有漂亮, 就像我年轻的时候那样。

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2. You know, like when you get headsets at the museum?  

你知道, 就像参观博物馆的那种助听设备?

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3. I want to see how the pot looks like when you have burnt it.  

我想看看你烧出来的陶器是什么样的。

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4. Like when I had to sell pancakes to this school soccer captain?  

就像我每次卖煎饼给学校的足球队长?

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5. You know, like when a girl kisses a frog and the frog turns into a prince.  

当你去亲吻一只青蛙, 当青蛙在你的亲吻下变成王子时。

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