Hotmail crashes. Had call from India from ‘windows’ & she spoke about ‘prefetch’. Was suspicious & hung up but was probably ok. How can I fix it?

Hotmail freezes & I get message to say Internet Explorer has stopped working & it has to close & reopen.  It's only started recently.  When I got the 'international' call from India, it was difficult to understand her accent & when she started to tell me to enter prefetch into the start menu, I couldn't verify who she was, so I hung up.  I think now that she was ok, but you have to be so careful these days with lots of scams around, b ut any idea how I can fix this problem, or do I have to pay for a programme to clean it up?