Cant find file while installing

So, I'm having a problem installing the base game of the Sims 3. 
I have installed and played downloaded games before, I generally know how it works and what I have to do but this time I'm completely stuck.

I've succesfully unpacked the .iso file. 
I've mounted the StartDisk file, installation guide started as usual.
Then half way through the installation it asks for the disk. 
I tried to find the file I opened before (I thought that was what the installation guide was telling me to do) but I cant find the folder. The only folder recognised by my computer is the crack folder. 
I first thought of sending it to D:\SIMS3. It wouldn't do that. 
Then I tried manually sending it to where I know the file is. Like C:\documents\blabla\TheSims3\The_Sims_3_Disk_1 , it wouldnt do that either.

Please help me! 

//EDIT

NEVERMIND:noob: 

I searched the forum a bit more thourough and found an older post by someone with a similar problem, I didnt give my computer 3 drives, just 2 .. 

Sorry. But nice forum! I'll be back.. 


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