I too faced a lot of probs from a HP service centre at Bangalore.
I have adequate knowledge on my lappie... and pointed out that my dvd writer is faulty... but those guyz were just adamant that the os is at fault. after a week of repairs (for a crashed vista ultimate 64bit) and "writer testing", they gave me the lappie. Thankfully I checked it's "writing skills" there itself and showed them the problem again.. after they installed the OS fresh. They were still blaming the os..... another week of testing... (and a suggestion from my side to check with another dvd writer!!!) l8r, they pointed out that the drive was faulty (check out the loop) and took another week to get a new dvd writer installed.
Loss = 2-3 weeks of my precious lap time
Another news I got....
HP will not install the OS from now on. We will have to bring in an original OS disc (even if we purchased the system with the OS as a legal addition in the package) when bringing for repairs. I bought my 17" (now is there a coincidence here) HP 9311TX for ~100000 (last June) because of it's extraordinarily good display and Vista Ultimate 64bit OS combo. And now they want me to buy an original OS disc and (to top it all).. take it to them for installation (and replication

). Now why did I pay that premium for my lappie? I expect a full software service in the service period.
Real pissed off with the guyz here. They r not even good in their own fields.... all rut maarke aaye lagte hain... following standard protocol.... of debuggin.... even when the answer is staring them in their face.... loonies...