Converting basic disk to dynamic disk

The simple answer to your question is: yes, you can change the drive from basic todynamic without losing data. However, thing can an do go wrong. If thing go wrong during the conversion process, data can be corrupted. Therefore it is prudent that you have a current backup available before attempting this.

The presence of pre-existing partitions will not affect the conversion process itself, nor your ability to mirror the partitions. However, partitions that existed prior to the conversion to dynamic disk cannot be extended (hence, the reason the system/boot partion cannot be extended using the Windows Disk Manager).

Hope this helps.

Dynamic disk will only support single partition but partition can be extended after convert to dynamin disk.
You will not lose any data if you convert basic to dynamic disk but data will be lost if you want to convert back.
Check this site for more info.
http://www.labmice.net/Windows2000/diskmgmt/dynamic_disk.htm