This is at Fidelity, right? You can still use the exact same investment options as when you were a Microsoft employee, you just can't add to the account. The Microsoft 401k has some of the lowest fee investment options out there, so when I left MS and analyzed my options, I decided to leave my money in there instead of rolling it over. Do you have a NetBenefits account for the website? If not, you'll have to call Fidelity, but they should be able to sort you out pretty easily.