Help! Please. Not sure how much information to put, or how to lay it out, so I have done the best I can. Sorry it is so long. Other half's Toishiba SatellitePro has just broken itself! Running Win 7 Pro 32 bit. Not a new machine been running fine for a while now. Hardware all seems OK. It may be linked to the latest batch of MS updates, which won't install as 4 of them are .net. It has fallen over or corrupted something in .net & / or windows installer. However, as it seems that both the Windows installer & .net 4 are both "broken" and it also seems that they require each other for a fix? i.e. .net4 requires Windows installer for a fix & vice versa? I've just spent 2 hours searching on the internet for fixes, & have run the MS .net repair tool, which fails. SFC/scannow also fails & chkdsk won't run as the volume is locked, both even in command prompt safe mode, and when chkdsk is set to run on next boot, it does not! Don't have an install disk as it is a laptop which came pre-installed. Trying to avoid a total restore to factory due to the time to rebuild the software on the machine, it runs our small business accounts, we do have an accounts backup & a backup of the documents folder. It just seems that it is .net & installer that are affected. When installing the latest round of MS updates: Outlook update KB2768025 fails with error Code 91A Windows Update encountered and unknown error, and there is little other help available. Tried a few "Microsoft FixIt" repairs for installer & .net they won't run as it seems they rely on each other? The .net error that occurs is: Unhandled exception has occurred in a component in your application. If you click Continue, the application will ignore this error and attempt to continue. Could not load file or assembly 'Accessibility, Version=18.104.22.168, Culture=neutral. PublicKey Token=b03f5f7f11d50a3a' or one of its dependencies. The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131407). The machine is not used for programming at all, just for "office" type applications. I have copied the text of the extended error message into the attached file. Thanks for looking. Please anyone, all help gratefully accepted!!!