But, before you go to that kind of drastic measures-booting in Recovery mode is a last ditch fix--you should see if there's an easier fix for your stalled out Windows Explorer.
To do that, if you're the PC's administrator, click Start, and then type cmd in the Run box to get to a MS-DOS shell. If you're an ordinary user, click Start again and use the Search box to find cmd. Then, right-click cmd.exe in the results box and then click Run as administrator. You will be prompted to type the password for an administrator account. Click Continue if you are the administrator or type the administrator password. Then, click Continue.
Once you're at the command prompt, type Sfc /scannow, and then press ENTER. This is Windows' System File Checker. It does exactly what it name says: it checks that the Windows' most important system files are in good shape.
System File Checker will try to repair any corrupted or missing files that it finds. If it runs into problems, it may also require you to enter your XP CD or DVD. And, again, if you don't have one of those, you're out of luck.
And people wonder why I favor Linux where you can always get another copy of the operating system so long as you have net access! Be that as it may, my best advise to you is, "If you're using XP, Don't upgrade with the MS10-015 patch until Microsoft has the bugs cleaned out of it."