If you find that your Windows 7 or Windows Server2008 R2 is rather slow to start up, these days, you may, inter alia, also want to check out the number of sytem restore points your computer has.
It may happen that you may have created many system restore points manually. If this is the case, it could increase your Windows 7 startup time.
The reason for this is as follows:
Volsnap.sys is a system file found in C:\Windows\System32\drivers and also in C:\Windows\System32\DriverStore\FileRepository\ too.
ReadyBoot (Not ReadyBoost) is boot acceleration technology that maintains an in-RAM cache used to service disk reads faster than a slower storage medium such as a disk drive. ReadyBoot reads (prefetches) data into the cache before it is requested. Prefetching optimizes disk access patterns by taking data locality and hard drive’s performance characteristics into account. Read requests from system processes, services and user applications are then serviced out of the ReadyBoot RAM cache.
Now during every startup, this file Volsnap.sys has to validate the snapshot of Windows, that each system restore point creates. Now if you have too many restore points, the boot plan for the ReadyBoot feature will exceed the size limit of 512 KB, and cannot be stored. This boot plan is stored in the following registry entry:
In such cases, therefore, the startup I/O operations are not pre-cached resulting in a slow startup.
So if you do face a slow startup, you might also want to consider checking up your number of system restore points. To resolve this issue, you can also apply for an get HotFix368028 from KB2555428. Do so, only if you are regularly facing this problem.