Indeed there are people “quite proficient in hacking personal information” working in Indian call centres, as the link I posted previously shows, and Dell have call centres in India. I would suggest that the fact that the caller knew you had a Dell computer indicates that Dell’s customer information has leaked, despite what they say.

I find it highly unlikely that it was just a cold call.

In fact a little Googling adds more evidence:

Hmm, that's interesting. I bought a Dell PC recently, and had to deal extensively with their Indian call centre when it turned out to be pants and deserving of a full refund. Shortly after, I got one of those scam calls. It does sound like someone in a legit call centre is passing on phone numbers.

http://www.guardian.co.uk/technology/blog/2010/jul/20/phone-calls-india-scams

Be very careful if someone rings you saying they are from Dell and telling you that you have a virus etc.etc.

A man rang us today – he knew our name - knew we had a Dell computer and he was ringing to inform of a serious virus affecting Dell computers which could not be detected by Virus programs.

http://uk.answers.yahoo.com/question/index?qid=20110401132754AAAn3CR

I can’t see any examples of people saying “They said I had a Dell computer but I don’t, so I knew it was a scam”, which you’d expect if they were just trying their luck.