ProDJay: Posted and copied from another forum and concerns Win XP and Win 7 32 & 64 (not tested on Vista):
Once the machine choice has been made, the next and most crucial move, is to buy a fresh copy of the operating system and install that new operating system after partitioning the machine thus removing all the unimaginable amounts of superfluous, unwanted, unneeded, and resource hogging crap every machine comes with. How to do that is another complete and lengthy, but easy to follow topic.
The aforementioned details will help remove the luck factor and replace it with a skill factor when making the move to a new laptop. Regardless of the computer style, make, and/or model, some of the oldest tweaks and recommended parameters haven't really changed since Win95.
For a device with one large internal drive (and it's the ONLY drive, boot and all), make three partitions.
Drive C: is OPERATING SYSTEM and PROGRAMS ONLY !! 60gb - 100gb should do it. All environmental variables such as My Documents, My Videos, My Pictures, MY "anything" should be changed to your D: drive). Cloning is so much more efficient and of shorter duration when it's operating system and program only on the C:\drive.
Drive E: is the swap file drive. Determine its size by taking your max ram in gb x 1024 x 3. Lets say your machine is capable of 12gb ram. 12gb times 1024 times 3 would be 36gb, so make it 40gb. By having a swap file on its own partition, one can either custom frame the sizing or let it run free however with no data other then the swap file, swap file commingled with data fragmentation never becomes an issue.
Drive D: is the data drive. Everything other than the operating system, the programs, and the swap file, resides on this drive and Drive D: is all the remaining available space.
Realizing this is a lot of work up front, the beauty of this design saves enormous amounts of backup/restore grief as well as squeezes every last bit of performance horsepower out of any machine.