How do you use all of the drive without partition

Good Afternoon:
I have a stupid question that I need a answer to. I bought a compaq sr2100wm for my son for xmas at only has been 2 month and the hard drive went out , HP send me a 80g hard drive and a set of boot up disk. Now for some reason my first set of boot up disk dint work and they send me a second set.

Here is my question. For some reason my hard drive is partition in 3 places , C,D,E.

C: has 15.6
D: Has 50.4
E:8.4 recovery partition is almost all full.

I would like to combine C and D together without loosing window xp home edition, due to the fact I had lots of problem installing them. Is there a simple way to do this without loosing data.

Second question is what is Ultra hard drive and Eide hard drive. I would like to upgrade in the near future to a bigger hard drive and would like to know what is the difference and can I upgrade with out loosing any data to the new drive. Thanks you so much . MrGordy

 

Well in order to answer the first part of your question go here

and to answer the second part of your question see here