If read-only access to shared drive possible, why allow read-write?

[humbug]

I'm not comfortable allowing my late-2011 WD TV Live to have read-write access to my WinXP and Win7 shared drives. If I use a guest account with read-only access to those shares, can I expect my player to work as well as with read-write access? If not, what problems/loss of function should I expect to see? What functionality is worth allowing read-write access to those shares? Thanks for relevant advice.

[TonyPh12345]

If you're talking about the device that this forum is about (The WDTV Live / WDTV Live +)

The ONLY loss of function I'm aware of is that the RESUME function for DVDs will not work.

If you're talking about the WDTV Live Streaming Media Player that was INTRODUCED in 2011, then there's LOTS that won't work if it doesn't have write access, and you're in the wrong forum.