whats the names of the files? it could be a page file. MS states that its better to put your page file on a drive that doesn't have the OS on it.
In spite of the name 'virtual memory' the paging file is really just a chunk of reserved hard drive space where data may be written and retrieved as needed. Since the paging file and operating system files are by default located on the same drive, concurrent access to both locations is impossible. One or the other has to wait, slowing down overall system performance. What can you do to minimize the delay? If your system only has one hard drive the best option is to pack the motherboard with as much RAM as possible to minimize paging file accesses.
If the operating system has more than one hard drive, place the paging file on a drive which does not contain the operating system files. A step up from placing the paging file on a separate drive is to place it on a dedicated drive. Even if you don't have a drive to dedicate solely to the paging file, placing it on a different drive that contains files which are not accessed frequently will help the performance issue.
If more than two hard drives are available, the paging file can be split among different drives. The more drives that are available to split the paging file across, the better the performance increase. Even though it's outside the scope of this article, paging files should not be placed on fault-tolerant drives because of the way data is written to them. It looks like 'the more paging files the better' corollary is applicable, and to a point that is true, with one major exception. Do not place more than one paging file on multiple partitions on a single physical hard disk. Performance will decrease because the drive heads perform sequential accesses to different locations on the drive rather than pulling the information from one contiguous location.
Finally, the temptation is always great when you have a RAM packed machine to totally eliminate the page file. Don't do it. By design, some components in Windows XP require the presence of a page file, even if they never use it for its intended purpose. You'll likely receive out of memory type errors if you eliminate all page files. Feel free to set the page file to the required minimum (2MB) if you have sufficient RAM, secure in the knowledge that XP won't access the page file unless it's absolutely needed, but again - don't eliminate it totally.