laptop will not run except in Safe Mode

My daughters top notch Laptop, (forgot its name & gonfig) sudenly will not run except in Safe Mode.
The experts at the university said:-
"....now they used Safe Mode & have most of my files saved on an external drive....."
"..... They are very puzzled - they aren't sure if its hardware or Windows problem. at first they thought it was hardware, but when it opened in Safe Mode, they then thought it must be software....."
"......they will reload the Vista software - if that fails, then they will know it is hardware......."
Anybody had similar problem?
Can anybody beat the University boffins?
The experts at the university said:-
"....now they used Safe Mode & have most of my files saved on an external drive....."
"..... They are very puzzled - they aren't sure if its hardware or Windows problem. at first they thought it was hardware, but when it opened in Safe Mode, they then thought it must be software....."
"......they will reload the Vista software - if that fails, then they will know it is hardware......."
Anybody had similar problem?
Can anybody beat the University boffins?