The motherboard was changed last time. When the problem persisted, I got in touch with DELL India...& that's how I landed up with an excruciating series of email exchanges with Lalitha. It was like trying to explain Dark Matter to a retard. Anyway, I finally convinced them to send me a systems engineer (who turned out to be the previous one). This time they reinstalled the OS.
The problem has only been aggravated. DELL India now intends to change the hard disk and RAM. They'll hopefully show up on Saturday.
What have I done to deserve this? It's like marrying a hottie with schizophrenia.