yes you can safely just delete this .dmp file as its only used if you send the info to microsoft for error reporting.
click start/run and type *.dmp to search for all dump files and delete them.
check in control panel performance and maintenance/system/error reporting and tick "disable error reporting" and tick "but notify me when critical errors occour"
then click the start up and recovery/settings tab /write debigging information and select "small memory dump 64kb" maybe.
for general cleanup of temp files etc use start/my computer/right click your hard drive/properties/general/disk cleanup or try click here which is more effective in my opinion and quite safe to use if you wish to free some disk space.