My mac says I don't have 2gb of memory when i have 90gb

The 2GB requirement is for RAM, not disk space. Buy the RAM from a source such as Crucial or OWC.

(138839)

Storage and Memory are not the same. You can have 90Gb of storage but still have only 1GB of RAM memory.

Go into the Apple Menu->About This Mac, and see how much RAM it says you have. a 2011 Mac Mini should have at least 2GB, unless one of the memory modules failed.

You will not be satisfied with performance with only two GB of memory. Yu Mac can take 16 GB (2x8).

If you do not want to go to 16 I would replace one stick with an 8 GB stick. This place sells compatible memory and have a video for how to replace the memory

http://eshop.macsales.com/shop/memory/Apple_Mac_mini/DDR3_1333

The base 2011 came with 2 GB (2x 1GB).

Try reseating the RAM if inspection shows 2 sticks installed

http://support.apple.com/kb/HT4432

You’re using a 2009 Mac, not a 2011 one, and need to buy more RAM for it.

(138840)

You have an early 2009 and the baseline comes with 1x1 GB memory. To upgrade see:

http://eshop.macsales.com/shop/memory/Apple_Mac_mini/DDR3

Your Mac maxes out at 8 GB (2x4 GB).

Click here and check if they use the same RAM type.

(138844)

You should not post the serial number of your system in this open forum. I asked hosts to edit it out but reposted the non-SN part of the picture in case the entire image vanishes.

Chris Felder wrote:

I have a broken MacBook pro 13' can i takeout he memory from that?

You'll need to know the specific year/ model of MacBook Pro. but its very possible it can work. They need to use the same type of RAM.

The MacBook Pros 5.1 through 7.1 (late 2008-mid 2010) use the same memory as the 2009 Mac mini

Yes. Which is why we need to know the exact year of the MacBook Pro.