Share your experience!
I bought Xperia Mini (ST15i) last month with Android 2.3.3 (4.0.A.2.368). After a few days it showed that new system update 4.0.A.2.377 was available. I have installed PC Companion on a brand new PC running Windows 7. When I run PC Companion it also shows "A phone software update is available". But I am unable to update my phone.
In the "Phone Software Update", there are 4 stages: Start, Prepare, Update, Finish. It reaches the 2nd stage (Preparing computer for software update) where it first shows "Downloading..." then "Preparing...". After that it immediately gives Installation Error (Unable to install or start phone software update components).
I tried various possibilities but did not succeed. I disabled firewall, uninstalled anti-virus and restarted the system, but it did not work. I also checked "allow installation of non-market applications" in the phone, it also did not work.
Now there is a newer update 4.0.2.A.0.42 available. But again I an unable to update the phone. I have tried it many, many times. Kindly help.
Hi, try updating with SE Update Service, here's the download link, http://dl-www.sonyericsson.com/cws/download/1/110/61/1317636927/Update_Service_Setup-2.11.10.7.exe
Reminder .... backup your phone data.
Try the following to resolve this issue,
1. Close PC Companion
2. Install java from http://www.java.com/winoffline_installer
3. Start PC Companion again and try to do the SW Update of the phone.
Successfully updated.
I reinstalled java, again disabled firewall, uninstalled anti-virus, but it did not work. Then I used a different PC (laptop) and it simply worked (without disabling firewall or uninstalling anti-virus). Perhaps some security set up on earlier PC was not allowing all this.
I thank the Moderators for responding to my queston.
Great! Glad that you have sorted it out. 
Enjoy your phone with the updated Android OS ....