IS Protector or Disk Wipe may help u that u want. Before doing anything, please take necessary backups of important data !
How about bit locker to do the encryption. It is built into Windows.
If I am not wrong, Bitlocker is available in Vista and windows 7.... And it is bit difficult to configure it. Though this is an in-built system. With BitLocker basically have two different ways to protect : A TPM chip and Using a clear key, which is simply a normal password protection method. TPM chip version 1.2 is required and a BIOS is TCG version 1.2 is required to work with BitLocker. It is a full-volume encryption tool that supports custom protection and authentication methods but not to help to wiping.
@ TeachMeIT, asked for free encryption SW that has capability of remote wiping. I provided the free SWs that meet the both criteria. There is also a tool called "ActiveSync remote wipe tool" which can use for the same.
Although not free, the www.Endpointprotector.com offers some encryption, white listing, file tracing and file shadowing which are all great for forensics. The product also provides policy based management, integrates with AD and supports MACs.