Urgent I cannot start my vista home edition after I update my comp

Dear All:

I open my computer, then show " windows loading files, then startup key

repair, I put my recovery dvd inside, I want to completely start restore the

PC, but cannot find the DVD drive location .Then I choose system restore, but

it failed and show"System Restore failed due to an unspecified error. Not

enough storage is available to complete this operation (0X8007000E)! the

instruction at 0x743c2738 referenced memory at 0x00000004. the memory could

not be read"

Any reply will be appreciated!