How to upgrade Windows Mobile software on iPAQ?

[jeriffstive]

Have iPAQ hx2000 series running WinMobile2003; purchased 2005. How do I install the new OS without destroying or losing my current data? People have said it's hard. Does it make sense to buy a new PDA instead??but they're so pricey! If so, which PDA that runs on WIndows Mobile OS would you recommend? And which products give great customer service (have not been pleased w HP). Thank you so much! Alternatively, should I leave the PDA's behind and buy a "smart phone" or Blackberry? Thank you so much!