If it is the hard drive, you can plug in an external drive and continue using it.
If it isnt the hard drive, and you choose to replace it, you have no option of what DVR they send as a replacement, unless you upgrade to the HR34 (HMC) which will cost you between $99 and $399 depending on your account status. If you want a specific DVR, such as a HR24, you would need to contact DirecTv and see if they will authorize you to obtain the DVR from a retailer online, and get credit for it on your bill when you deactivate and return the HR22. Sometimes they do this, sometimes they dont. Luck of the CSR draw there.
If it isnt the hard drive, and you choose to replace it, you have no option of what DVR they send as a replacement, unless you upgrade to the HR34 (HMC) which will cost you between $99 and $399 depending on your account status. If you want a specific DVR, such as a HR24, you would need to contact DirecTv and see if they will authorize you to obtain the DVR from a retailer online, and get credit for it on your bill when you deactivate and return the HR22. Sometimes they do this, sometimes they dont. Luck of the CSR draw there.