locked out of windows

I recently installed some additional memory into my HP pavillion xt963, all was fine for a moment then suddenly the computer restarted itself. A black screen appeared that says "we apoligize for the inconvenience but windows did not start successfully.A recent hardware or software change might have caused this. If your computer stopped responding, restarted unexpectedly,or was automatically shut down to protect your files and folders,choose last known good configuration to revert to the most recent settings that worked.
If a previous startup was interrupted due to a power failure or because the power or reset button was pressed, or if your not sure what caused the problem, choose start windows normally.
then it shows
Safe Mode
Safe Mode with Networking
Safe Mode with Command Prompt

Last Known Good Configuration (your most recent settings that worked)
Start windows normally
Tried all settings safe mode wont let me in goes to a blue screen with an error that reads Unmountable_Boot_Volume and asks to check that hardware or software is installed correctly (done this , even removed new memory completely) suggests safe mode if problem persists (it does) disable biosmemory options such as caching or shadowing but cant get in safe mode to do this help this idiot please
Thanks loads
Jess

 

You may need to boot into your Bios and check the memory settings. You could even try changing the Bios from Default to Performance then save and exit. Also are you sure the stick of memory is compatible for the laptop?

 

Thanks but still no work headed to shop thanks for trying

Jess

 

Run the harddrive manufacturer's utilities. They can analyse a drive and often point you in the direction of a solution.

Boot to the CD that came with the computer and see if there are diagnostics.
Edit: Check the HP support website for your model (utilities or downloads), also search for "unmountable boot volume ".
www.hp.com/support

If you take it to the shop you will learn nothing

Matt