This is not a common error message and it tends to come with another. Firstly the 0x800700A1 code
relates to "ERROR BAD PATHNAME". It pops up rarely and it comes with 0x800700C1 "ERROR BAD EXE FORMAT" in some cases. I traced the problem to a dodgy partition but only by chance as curing the "ERROR BAD EXE FORMAT" cured the 0x800700A1
error as well. Delete the existing partition if you have not done so already and give the disk a format using Symantecs Partition Magic or another such utility. Check for bad sectors as well on the disk.