I advise clean installation, cloning or using DBAR with Cache drives is nothing but trouble. You should be able to call Dell Technical Support to request a Windows 7 Reinstallation DVD however I would recommend using a Digital River .iso instead: [URL] Install without a product key and use the Activation Backup and Recovery Program to restore the OEM product activation: [URL] Follow my Windows Reinstallation Guide/A Clean Install of Windows: [URL] Note: You will need to format the conventional hard drive otherwise you may form some sort of dual boot. So backup all data to an external hard drive. Before installation you will need to change the BIOS setup to AHCI or the mSATA drive will be used as a cache drive (and its pointless using a 500 GB mSATA drive as a cache drive). Once the data is backed up you may use the Windows disc to delete all partitions or use DBAN to securely wipe the drive. It is also possible for you to replace the mSATA drive and remove the conventional hard drive. You can then change the SATA operation in the BIOS setup to AHCI and begin the Windows installation; If something goes wrong you may revert the change in the SATA operation and reseat both original drives. Once you have the Windows setup on the mSATA the way you want it, you may remove it and seat the conventional drive and then begin its wipe with DBAN. After securely wiping you can reseat the new mSATA drive with Windows 7. Once Windows 7 is loaded you may open disc management to setup a new drive see here: [URL]
My equipment: L521X with windows 7 64bit home edition 32GB mSATA (even if only 8GB are used) and a 750gb HDD I've been doing some reading and it seems what I want to do is not so easy. I want to upgrade the size of the mSATA to 500GB. Then I want to install the installation CD's to the mSATA partition and just use the regular 750Gb hard drive as storage.  A few challenges I read about: * I cannot use the DBAR (recovery disks) to do this * I have to resintall from scratch * I have to buy a Windows 7 OS disks separately, and then install all the relevant drivers. * I have to disable IRST acceleration first before install and then disable IRST in BIOS.  Questions: * Can I not just direct the install drive to be mSATA from the get-go?  * I figure I cannot clone the 750Gb HDD drive even if only 100GB is used to a 500GB mSATA? Hence a re-install?  * Is the limitation being that the DBAR resides on a encrypted partition? (or something like that). Hence the DBAR cannot be used to install on mSATA?  * As a workaround if above setup doesn't work, can I not just unplug the HDD to install on mSATA? if I plug it back in, will BIOS treat the HDD as the primary? (I figure there are no switches to move here or BIOS settings?).  I figure I won't need IRST anymore if I upgrade the mSATA size and just use the regular HDD as a storage.  I don't have a need for UEFI even if that may speed things up since I don't see my having more than 2GB partitions.  I can just go the SSD route but it seems a waste to not utilize the regular 750Gb hdd if I want to keep the blueray drive still. 
Upgrading mSATA size and putting windows 7 in it - L521X