I encounter this problem several times, the way to get around this is to give "Everyone or Network Service " permission to "C:\windows\temp" folder. I gave everyone on my development box just for convenient.
I hope it will help you solve the same problem as I had.
Here are some references:
"It is enough to give read, write permission to NETWORK SERVICE user. crystal report create a temp file with guid for name in windows temp folder, so it needs write permission to the disk to make create that temp file."