My SSD (Intel 335 Series Jay Crest 180GB) is in read-only mode. I have Windows 8.1 Pro installed on it. I am unable to install any Steam games on it because the drive is read-only. I tried changing the permission in the properties menu but it did not work.
I am sorry for this issue.
Perhaps you may need to verify if your account has the necessary administrator rights or privileges to install the desired software.
You may use the https://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=18455 Intel® SSD Toolbox just in order to discard any hardware issue.
I just ran a quick and full diagnostic which found no issue. The firmware is also the latest version. I right clicked on the drive and gave my account permission to read, write, execute, and modify but that did nothing. I also tried to change the folder Steam needs to write to to writable but the read-only attribute gets applied right away. I think this may be an issue with Windows 8.1 more than the SSD.