Basically when an error occurs, say a blue screen of death (BSOD) Windows gathers all available information stored in memory at the time of the incident and 'dumps' it into a file. The file can then be used by a support engineer to determine what could have
possibly caused the error in the first place. Sometimes, when an error occurs Windows will ask if it can sned furhter information to Microsoft. If you press the Yes button on the request message that appears, then Windows will upload the dump files to Microsoft's
Dump files are useful 'but' they do have a nasty habit of taking up a lot of disk space, therefore it is beneficial to remove the files to get back the space they take up. Personally I use a thrid party freeware application called CCleaner (www.piriform.com)
If you use this and look down the left hand side of the CCleaner window you will see a list of options that it removes. 'Remove Windows Error reports' isn't ticked by default, but I do tick it every few weeks or so, so that it clears out all the old error
resports that are no longer needed.
So, in answer to your question, Yes they can be deleted.
This forum post is my own opinion and does not necessarily reflect the opinion or view of Microsoft, it's employees, or other MVPs.