How to access windows partitions from VL 5.8 standard on a dual boot machine ?
I hope this won't be taken as telling you to RTFM, but this question is covered in the documentation that is accessible right on your desktop in 5.8 Standard. Open Vector-Docs (there's an icon on the default desktop). Scroll down to Documentation/Help. Click on VectorLinux Manuals. When that comes up, click on Accessing local disks and partitions. That will give you as much as you need to know to mount and access Windows file systems.
I note that the explanations and examples do not seem to cover making an NTFS partition writable with ntfs-3g. If you have NTFS partitions you would like to write to, post a question here and someone will help you. You should also find the answer to that through a forum search, if the answer wasn't lost when the forum was reorganized or something and we lost a bunch of HowTo's and valuable forum messages.
It is faster, more efficient, and more empowering to learn to use the documentation we already have than to post questions in the forum and hope someone answers. If you don't understand something you read, don't have any luck after trying something you've read, or can't find what you need to know, forum members are more than happy to try to help.