I'm trying to upgrade my laptop from xp to win 7,how can i backup/copy my files and pics so i can do a clean install,but xp only backups to a ''removable storage device'',not a cd/dvd
You do not have to use a "backup" command or program.
You can use COPY or XCOPY (preferred because of "verify" switch) from the DOS command prompt.
You can use Edit/Copy and Edit/Paste from a Windows Explorer menu bar.
You can use freeware backup software.
You can use freeware partition/drive imaging software.
As John suggested, simply add an external USB hard drive, partition and format (unless creating a partition/drive image, but be careful!!!), then choose one of the above. It will help, termendously, if you know exactly where the files/pics/etc. are located. Let us know and we'll walk you through it.
The external hard drives can and do crash also. I've had 2 laptops and my seagate external hard drive crash. CD is a hard copy. It can't crash like any hard drive can. Everything I thought I had backed up safely was lost. I double back up any thing that I really need to save.
Back up to optical media (CD/DVD) provides for "safer" storage of data while in use in the sense that failure of the drive or read/write mechanisms will not corrupt information already burned onto the media. Failures of optical drives do occur and, on rare occasions, require disassembly to retrieve the disk. If the CD/DVDs are out of the drives, they can be damaged if not handled/stored correctly.
Back up to hard drives provides for "faster access" to data while in use in the sense that one does not have to locate the CD/DVD, load and retrieve information from it. Hard drive failures are often preceded by warning symptoms that should be addressed, immediately (i.e., copy data off the failing drive), lest catastrophic failure occur. What most clients I have worked with who have experienced hard drive crashes have said was that they were hoping the symptoms would "go away" and, in effect, "hard drive, heal thyself." Once a hard drive starts going, you cannot stop it. It may take a little or a lot of time, but it will, eventually, crash.
Thus, it's a matter of preference: access time to data (because for some individuals/businesses, time is essential and time is money) or "perceived" safer storage of data. In either case, copying of the data off the primary storage location is achieved.